# The Mutt Next Generation E-Mail Client

Andreas
Krennmair
ak@synflood.at
Michael
Elkins
me@cs.hmc.edu
version @VERSION@

Michael Elinks on mutt, circa 1995: ``All mail clients suck. This one just sucks less.''

Sven Guckes on mutt, ca. 2003: ``But it still sucks!''

## Introduction

### Overview

Mutt-ng is a small but very powerful text-based MIME mail client. Mutt-ng is highly configurable, and is well suited to the mail power user with advanced features like key bindings, keyboard macros, mail threading, regular expression searches and a powerful pattern matching language for selecting groups of messages.

This documentation additionally contains documentation to Mutt-NG ,a fork from Mutt with the goal to fix all the little annoyances of Mutt, to integrate all the Mutt patches that are floating around in the web, and to add other new features. Features specific to Mutt-ng will be discussed in an extra section. Don't be confused when most of the documentation talk about Mutt and not Mutt-ng, Mutt-ng contains all Mutt features, plus many more.

### Mutt-ng Home Page

### Mailing Lists

- mutt-ng-users@lists.berlios.de: This is where the mutt-ng user support happens.

- mutt-ng-devel@lists.berlios.de: The development mailing list for mutt-ng

### Software Distribution Sites

So far, there are no official releases of Mutt-ng, but you can download daily snapshots from

### IRC

Visit channel #muttng on irc.freenode.net (www.freenode.net) to chat with other people interested in Mutt-ng.

### Weblog

If you want to read fresh news about the latest development in Mutt-ng, and get informed about stuff like interesting, Mutt-ng-related articles and packages for your favorite distribution, you can read and/or subscribe to our Mutt-ng development weblog.

### Copyright

Mutt is Copyright (C) 1996-2000 Michael R. Elkins <me@cs.hmc.edu> and others

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

### Manual Conventions

This manual contains several (hopefully consistent) conventions to specially layout different items in different fashions.

- Configuration and environment variables will be printed in a typewriter font and both prefixed with a dollar sign as it's common for UNIX-like environments. Configuration variables are lower-case only while environment variables are upper-case only. is a configuration variable while is an environment variable.

- Muttng-specific functions are enclosed in `<>` and printed in a typewriter font, too, as in .

- As common for UNIX-like environments, references to manual pages are printed with the section enclosed in braces, as in or . Execute `man [section] [name]` to view the manual page.

- Keys are presented in the following way: ordinary keys are just given as-is, e.g. q. Control characters are prefixed with `C-` (e.g. the screen can be redraw by pressing L) and `E-` for Escape, e.g. a folder can be opened read-only with c.

If, while reading this fine manual, you find any inconsistencies of whatever kind, please contact the developers via mutt-ng-devel@lists.berlios.de to report it.

## Getting Started

### Basic Concepts

#### Screens and Menus

mutt-ng offers different screens of which every has its special purpose:

- The index displays the contents of the currently opened mailbox.

- The pager is responsible for displaying messages, that is, the header, the body and all attached parts.

- The file browser offers operations on and displays information of all folders mutt-ng should watch for mail.

- The sidebar offers a permanent view of which mailboxes contain how many total, new and/or flagged mails.

- The help screen lists for all currently available commands how to invoke them as well as a short description.

- The compose menu is a comfortable interface take last actions before sending mail: change subjects, attach files, remove attachements, etc.

- The attachement menu gives a summary and the tree structure of the attachements of the current message.

- The alias menu lists all or a fraction of the aliases a user has defined.

- The key menu used in connection with encryption lets users choose the right key to encrypt with.

When mutt-ng is started without any further options, it'll open the users default mailbox and display the index.

#### Configuration

Mutt-ng does not feature an internal configuration interface or menu due to the simple fact that this would be too complex to handle (currently there are several hundred variables which fine-tune the behaviour.)

Mutt-ng is configured using configuration files which allow users to add comments or manage them via version control systems to ease maintenance.

Also, mutt-ng comes with a shell script named `grml-muttng` kindly contributed by users which really helps and eases the creation of a user's configuration file. When downloading the source code via a snapshot or via subversion, it can be found in the `contrib` directory.

#### Functions

Mutt-ng offers great flexibility due to the use of functions: internally, every action a user can make mutt-ng perform is named ``function.'' Those functions are assigned to keys (or even key sequences) and may be completely adjusted to user's needs. The basic idea is that the impatient users get a very intuitive interface to start off with and advanced users virtually get no limits to adjustments.

#### Interaction

Mutt-ng has two basic concepts of user interaction:

1. There is one dedicated line on the screen used to query the user for input, issue any command, query variables and display error and informational messages. As for every type of user input, this requires manual action leading to the need of input.

2. The automatized interface for interaction are the so called hooks. Hooks specify actions the user wants to be performed at well-defined situations: what to do when entering which folder, what to do when displaying or replying to what kind of message, etc. These are optional, i.e. a user doesn't need to specify them but can do so.

#### Modularization

Although mutt-ng has many functionality built-in, many features can be delegated to external tools to increase flexibility: users can define programs to filter a message through before displaying, users can use any program they want for displaying a message, message types (such as PDF or PostScript) for which mutt-ng doesn't have a built-in filter can be rendered by arbitrary tools and so forth. Although mutt-ng has an alias mechanism built-in, it features using external tools to query for nearly every type of addresses from sources like LDAP, databases or just the list of locally known users.

#### Patterns

Mutt-ng has a built-in pattern matching ``language'' which is as widely used as possible to present a consistent interface to users. The same ``pattern terms'' can be used for searching, scoring, message selection and much more.

### Screens and Menus

#### Index

The index is the screen that you usually see first when you start mutt-ng. It gives an overview over your emails in the currently opened mailbox. By default, this is your system mailbox. The information you see in the index is a list of emails, each with its number on the left, its flags (new email, important email, email that has been forwarded or replied to, tagged email, ...), the date when email was sent, its sender, the email size, and the subject. Additionally, the index also shows thread hierarchies: when you reply to an email, and the other person replies back, you can see the other's person email in a "sub-tree" below. This is especially useful for personal email between a group of people or when you've subscribed to mailing lists.

#### Pager

The pager is responsible for showing the email content. On the top of the pager you have an overview over the most important email headers like the sender, the recipient, the subject, and much more information. How much information you actually see depends on your configuration, which we'll describe below.

Below the headers, you see the email body which usually contains the message. If the email contains any attachments, you will see more information about them below the email body, or, if the attachments are text files, you can view them directly in the pager.

To give the user a good overview, it is possible to configure mutt-ng to show different things in the pager with different colors. Virtually everything that can be described with a regular expression can be colored, e.g. URLs, email addresses or smileys.

#### File Browser

The file browser is the interface to the local or remote file system. When selecting a mailbox to open, the browser allows custom sorting of items, limiting the items shown by a regular expression and a freely adjustable format of what to display in which way. It also allows for easy navigation through the file system when selecting file(s) to attach to a message, select multiple files to attach and many more.

#### Sidebar

The sidebar comes in handy to manage mails which are spread over different folders. All folders users setup mutt-ng to watch for new mail will be listed. The listing includes not only the name but also the number of total messages, the number of new and flagged messages. Items with new mail may be colored different from those with flagged mail, items may be shortened or compress if they're they to long to be printed in full form so that by abbreviated names, user still now what the name stands for.

#### Help

The help screen is meant to offer a quick help to the user. It lists the current configuration of key bindings and their associated commands including a short description, and currently unbound functions that still need to be associated with a key binding (or alternatively, they can be called via the mutt-ng command prompt).

#### Compose Menu

The compose menu features a split screen containing the information which really matter before actually sending a message by mail or posting an article to a newsgroup: who gets the message as what (recipient, newsgroup, who gets what kind of copy). Additionally, users may set security options like deciding whether to sign, encrypt or sign and encrypt a message with/for what keys.

Also, it's used to attach messages, news articles or files to a message, to re-edit any attachment including the message itself.

#### Alias Menu

The alias menu is used to help users finding the recipients of messages. For users who need to contact many people, there's no need to remember addresses or names completely because it allows for searching, too. The alias mechanism and thus the alias menu also features grouping several addresses by a shorter nickname, the actual alias, so that users don't have to select each single recipient manually.

#### Attachment Menu

As will be later discussed in detail, mutt-ng features a good and stable MIME implementation, that is, is greatly supports sending and receiving messages of arbitrary type. The attachment menu displays a message's structure in detail: what content parts are attached to which parent part (which gives a true tree structure), which type is of what type and what size. Single parts may saved, deleted or modified to offer great and easy access to message's internals.

#### Key Menu

`FIXME`

### Moving Around in Menus

Information is presented in menus, very similar to ELM. Here is a tableshowing the common keys used to navigate menus in Mutt-ng.

#### Most commonly used movement bindings

Key | Function | Description
--- | --- | ---
j or Down |  | move to the next entry
k or Up |  | move to the previous entry
z or PageDn |  | go to the next page
Z or PageUp |  | go to the previous page
= or Home |  | jump to the first entry
* or End |  | jump to the last entry
q |  | exit the current menu
? |  | list all key bindings for the current menu

### Editing Input Fields

Mutt-ng has a builtin line editor which is used as the primary way to input textual data such as email addresses or filenames. The keys used to move around while editing are very similar to those of Emacs.

#### Line Editor Functions

Key | Function | Description
--- | --- | ---
A or Home |  | move to the start of the line
B or Left |  | move back one char
B |  | move back one word
D or Delete |  | delete the char under the cursor
E or End |  | move to the end of the line
F or Right |  | move forward one char
F |  | move forward one word
Tab |  | complete filename or alias
T |  | complete address with query
K |  | delete to the end of the line
d |  | delete to the end of the word
W |  | kill the word in front of the cursor
U |  | delete entire line
V |  | quote the next typed key
Up |  | recall previous string from history
Down |  | recall next string from history
BackSpace |  | kill the char in front of the cursor
u |  | convert word to upper case
l |  | convert word to lower case
c |  | capitalize the word
G |  | abort
Return |  | finish editing

You can remap the editor functions using the command. For example, to make the Delete key delete the character in front of the cursor rather than under, you could use

`bind editor <delete> backspace`

### Reading Mail - The Index and Pager

Similar to many other mail clients, there are two modes in which mail isread in Mutt-ng. The first is the index of messages in the mailbox, which is called the ``index'' in Mutt-ng. The second mode is the display of the message contents. This is called the ``pager.''

The next few sections describe the functions provided in each of these modes.

#### The Message Index

##### Most commonly used Index Bindings

Key | Function | Description
--- | --- | ---
c | `` | change to a different mailbox
c | `` | change to a folder in read-only mode
C | `` | copy the current message to another mailbox
C | `` | decode a message and copy it to a folder
s | `` | decode a message and save it to a folder
D | `` | delete messages matching a pattern
d | `` | delete the current message
F | `` | mark as important
l | `` | show messages matching a pattern
N | `` | mark message as new
o | `` | change the current sort method
O | `` | reverse sort the mailbox
q | `` | save changes and exit
s | `` | save-message
T | `` | tag messages matching a pattern
t | `` | toggle the tag on a message
t | `` | toggle tag on entire message thread
U | `` | undelete messages matching a pattern
u | `` | undelete-message
v | `` | view-attachments
x | `` | abort changes and exit
Return | `` | display-message
Tab | `` | jump to the next new or unread message
@ | `` | show the author's full e-mail address
$ | `` | save changes to mailbox
/ | `` | search
/ | `` | search-reverse
L | `` | clear and redraw the screen
T | `` | untag messages matching a pattern

##### Status Flags

In addition to who sent the message and the subject, a short summary of the disposition of each message is printed beside the message number. Zero or more of the following ``flags'' may appear, which mean:

D

  message is deleted (is marked for deletion)

d

  message have attachments marked for deletion

K

  contains a PGP public key

N

  message is new

O

  message is old

P

  message is PGP encrypted

r

  message has been replied to

S

  message is signed, and the signature is succesfully verified

s

  message is signed

!

  message is flagged

*

  message is tagged

Some of the status flags can be turned on or off using

- set-flag (default: w)

- clear-flag (default: W)

Furthermore, the following flags reflect who the message is addressed to. They can be customized with the variable.

+

  message is to you and you only

T

  message is to you, but also to or cc'ed to others

C

  message is cc'ed to you

F

  message is from you

L

  message is sent to a subscribed mailing list

#### The Pager

By default, Mutt-ng uses its builtin pager to display the body of messages. The pager is very similar to the Unix program less though not nearly as featureful.

##### Most commonly used Pager Bindings

Key | Function | Description
--- | --- | ---
Return | `` | go down one line
Space | `` | display the next page (or next message if at the end of a message)
- | `` | go back to the previous page
n | `` | search for next match
S | `` | skip beyond quoted text
T | `` | toggle display of quoted text
? | `` | show key bindings
/ | `` | search for a regular expression (pattern)
/ | `` | search backwards for a regular expression
\ | `` | toggle search pattern coloring
^ | `` | jump to the top of the message

In addition, many of the functions from the index are available in the pager, such as delete-message or copy-message (this is one advantage over using an external pager to view messages).

Also, the internal pager supports a couple other advanced features. For one, it will accept and translate the ``standard'' nroff sequences forbold and underline. These sequences are a series of either the letter, backspace (H), the letter again for bold or the letter, backspace, _ for denoting underline. Mutt-ng will attempt to display these in bold and underline respectively if your terminal supports them. If not, you can use the bold and underline objects to specify a color or mono attribute for them.

Additionally, the internal pager supports the ANSI escape sequences for character attributes. Mutt-ng translates them into the correct color and character settings. The sequences Mutt-ng supports are: `ESC [ Ps;Ps;Ps;...;Ps m` (see table below for possible values for `Ps`).

##### ANSI Escape Sequences

Value | Attribute
--- | ---
`0` | All Attributes Off
`1` | Bold on
`4` | Underline on
`5` | Blink on
`7` | Reverse video on
`3x` | Foreground color is x (see table below)
`4x` | Background color is x (see table below)

##### ANSI Colors

Number | Color
--- | ---
`0` | black
`1` | red
`2` | green
`3` | yellow
`4` | blue
`5` | magenta
`6` | cyan
`7` | white

Mutt-ng uses these attributes for handling text/enriched messages, and they can also be used by an external script for highlighting purposes. Note: If you change the colors for your display, for example by changing the color associated with color2 for your xterm, then that color will be used instead of green.

#### Threaded Mode

When the mailbox is sorted by threads ,there are a few additional functions available in the index and pager modes.

##### Most commonly used thread-related bindings

Key | Function | Description
--- | --- | ---
D |  | delete all messages in the current thread
U |  | undelete all messages in the current thread
N |  | jump to the start of the next thread
P |  | jump to the start of the previous thread
R |  | mark the current thread as read
d |  | delete all messages in the current subthread
u |  | undelete all messages in the current subthread
n |  | jump to the start of the next subthread
p |  | jump to the start of the previous subthread
r |  | mark the current subthread as read
t |  | toggle the tag on the current thread
v |  | toggle collapse for the current thread
V |  | toggle collapse for all threads
P |  | jump to parent message in thread

Note: Collapsing a thread displays only the first message in the thread and hides the others. This is useful when threads contain so many messages that you can only see a handful of threads onthe screen. See `%M` in .

For example, you could use `%?M?(#%03M)&(%4l)?` in to optionally display the number of hidden messages if the thread is collapsed.

See also the variable.

#### Miscellaneous Functions

a

Creates a new alias based upon the current message (or prompts for a new one). Once editing is complete, an command is added to the file specified by the variable for future use. Note: Specifying an does not add the aliases specified there-in, you must also the file.

P

This function will search the current message for content signed or encrypted with PGP the "traditional" way, that is, without proper MIME tagging. Technically, this function will temporarily change the MIME content types of the body parts containing PGP data; this is similar to the function's effect.

h

Toggles the weeding of message header fields specified by commands.

e

This command (available in the ``index'' and ``pager'') allows you to edit the raw current message as it's present in the mail folder. After you have finished editing, the changed message will be appended to the current folder, and the original message will be marked for deletion.

(default: E on the attachment menu, and in the pager and index menus; T on the compose menu)

This command is used to temporarily edit an attachment's content type to fix, for instance, bogus character set parameters. When invoked from the index or from the pager, you'll have the opportunity to edit the top-level attachment's content type. On the attach-menu, you can change any attachment's content type. These changes are not persistent, and get lost upon changing folders.

Note that this command is also available on the compose-menu .There, it's used to fine-tune the properties of attachments you are going to send.

:

This command is used to execute any command you would normally put in a configuration file. A common use is to check the settings of variables, or in conjunction with to change settings on the fly.

K

This command extracts PGP public keys from the current or tagged message(s) and adds them to your PGP public key ring.

F

This command wipes the passphrase(s) from memory. It is useful, if you misspelled the passphrase.

L

Reply to the current or tagged message(s) by extracting any addresses which match the regular expressions given by the commands, but also honor any `Mail-Followup-To` header(s) if the configuration variable is set. Using this when replying to messages posted to mailing lists helps avoid duplicate copies being sent to the author of the message you are replying to.

Asks for an external Unix command and pipes the current or tagged message(s) to it. The variables , , and control the exact behavior of this function.

e

With resend-message, mutt takes the current message as a template for a new message. This function is best described as "recall from arbitrary folders". It can conveniently be used to forward MIME messages while preserving the original mail structure. Note that the amount of headers included here depends on the value of the variable.

This function is also available from the attachment menu. You can use this to easily resend a message which was included with a bounce message as a message/rfc822 body part.

!

Asks for an external Unix command and executes it. The can be used to control whether Mutt-ng will wait for a key to be pressed when the command returns (presumably to let the user read the output of the command), based on the return status of the named command.

T

The pager uses the variable to detect quoted text when displaying the body of the message. This function toggles the displayof the quoted material in the message. It is particularly useful when are interested in just the response and there is a large amount of quoted text in the way.

S

This function will go to the next line of non-quoted text which come after a line of quoted text in the internal pager.

### Sending Mail

The following bindings are available in the index for sending messages.

#### Most commonly used Mail Composition Bindings

Key | Function | Description
--- | --- | ---
m |  | compose a new message
r |  | reply to sender
g |  | reply to all recipients
L |  | reply to mailing list address
f |  | forward message
b |  | bounce (remail) message
k |  | mail a PGP public key to someone

Bouncing a message sends the message as is to the recipient you specify. Forwarding a message allows you to add comments or modify the message you are forwarding. These items are discussed in greater detail in the next chapter forwarding-mail.

#### Composing new messages

When you want to send an email using mutt-ng, simply press m on your keyboard. Then, mutt-ng asks for the recipient via a prompt in the last line:

To:

After you've finished entering the recipient(s), press return. If you want to send an email to more than one recipient, separate the email addresses using the comma "`,`". Mutt-ng then asks you for the email subject. Again, press return after you've entered it. After that, mutt-ng got the most important information from you, and starts up an editor where you can then enter your email.

The editor that is called is selected in the following way: you can e.g. set it in the mutt-ng configuration:

set editor = "vim +/^$/ -c ':set tw=72'" set editor = "nano" set editor = "emacs"

If you don't set your preferred editor in your configuration, mutt-ng first looks whether the environment variable is set, and if so, it takes its value as editor command. Otherwise, it has a look at and takes its value if it is set. If no editor command can be found, mutt-ng simply assumes to be the default editor, since it's the most widespread editor in the Unix world and it's pretty safe to assume that it is installed and available.

When you've finished entering your message, save it and quit your editor. Mutt-ng will then present you with a summary screen, the compose menu. On the top, you see a summary of the most important available key commands. Below that, you see the sender, the recipient(s), Cc and/or Bcc recipient(s), the subject, the reply-to address, and optionally information where the sent email will be stored and whether it should be digitally signed and/or encrypted.

Below that, you see a list of "attachments". The mail you've just entered before is also an attachment, but due to its special type (it's plain text), it will be displayed as the normal message on the receiver's side.

At this point, you can add more attachments, pressing a, you can edit the recipient addresses, pressing t for the "To:" field, c for the "Cc:" field, and b for the "Bcc: field. You can also edit the subject the subject by simply pressing s or the email message that you've entered before by pressing e. You will then again return to the editor. You can even edit the sender, by pressing `<esc>f`, but this shall only be used with caution.

Alternatively, you can configure mutt-ng in a way that most of the above settings can be edited using the editor. Therefore, you only need to add the following to your configuration:

set edit_headers

Once you have finished editing the body of your mail message, you are returned to the compose menu. The following options are available:

##### Most commonly used Compose Menu Bindings

Key | Function | Description
--- | --- | ---
a |  | attach a file
A |  | attach message(s) to the message
k |  | attach a PGP public key
d |  | edit description on attachment
D |  | detach a file
t |  | edit the To field
f |  | edit the From field
r |  | edit the Reply-To field
c |  | edit the Cc field
b |  | edit the Bcc field
y |  | send the message
s |  | edit the Subject
S |  | select S/MIME options
f |  | specify an ``Fcc'' mailbox
p |  | select PGP options
P |  | postpone this message until later
q |  | quit (abort) sending the message
w |  | write the message to a folder
i |  | check spelling (if available on your system)
F |  | wipe passphrase(s) from memory

Note: The attach-message function will prompt you for a folder to attach messages from. You can now tag messages in that folder and theywill be attached to the message you are sending. Note that certainoperations like composing a new mail, replying, forwarding, etc. are not permitted when you are in that folder. The `%r` in will change to a 'A' to indicate that you are in attach-message mode.

#### Replying

##### Simple Replies

When you want to reply to an email message, select it in the index menu and then press r. Mutt-ng's behaviour is then similar to the behaviour when you compose a message: first, you will be asked for the recipient, then for the subject, and then, mutt-ng will start the editor with the quote attribution and the quoted message. This can e.g. look like the example below.

On Mon, Mar 07, 2005 at 05:02:12PM +0100, Michael Svensson wrote: > Bill, can you please send last month's progress report to Mr. > Morgan? We also urgently need the cost estimation for the new > production server that we want to set up before our customer's > project will go live.

You can start editing the email message. It is strongly recommended to put your answer below the quoted text and to only quote what is really necessary and that you refer to. Putting your answer on top of the quoted message, is, although very widespread, very often not considered to be a polite way to answer emails.

The quote attribution is configurable, by default it is set to

set attribution = "On %d, %n wrote:"

It can also be set to something more compact, e.g.

set attribution = "attribution="* %n <%a> [%(%y-%m-%d %H:%M)]:"

The example above results in the following attribution:

* Michael Svensson <svensson@foobar.com> [05-03-06 17:02]: > Bill, can you please send last month's progress report to Mr. > Morgan? We also urgently need the cost estimation for the new > production server that we want to set up before our customer's > project will go live.

Generally, try to keep your attribution short yet information-rich. It is not the right place for witty quotes, long "attribution" novels or anything like that: the right place for such things is - if at all - the email signature at the very bottom of the message.

When you're done with writing your message, save and quit the editor. As before, you will return to the compose menu, which is used in the same way as before.

##### Group Replies

In the situation where a group of people uses email as a discussion, most of the emails will have one or more recipients, and probably several "Cc:" recipients. The group reply functionalityensures that when you press g instead of r to do a reply, each and every recipient that is contained in the original message will receive a copy of the message, either as normal recipient or as "Cc:" recipient.

##### List Replies

When you use mailing lists, it's generally better to send your reply to a message only to the list instead of the list and the original author. To make this easy to use, mutt-ng features list replies.

To do a list reply, simply press L. If the email contains a `Mail-Followup-To:` header, its value will be used as reply address. Otherwise, mutt-ng searches through all mail addresses in the original message and tries to match them a list of regular expressions which can be specified using the `lists` command. If any of the regular expression matches, a mailing list address has been found, and it will be used as reply address.

lists linuxevent@luga\.at vuln-dev@ mutt-ng-users@

Nowadays, most mailing list software like GNU Mailman adds a `Mail-Followup-To:` header to their emails anyway, so setting `lists` is hardly ever necessary in practice.

#### Editing the message header

When editing the header of your outgoing message, there are a couple of special features available.

If you specify

`Fcc:` filename

Mutt-ng will pick up filename just as if you had used the edit-fcc function in the compose menu.

You can also attach files to your message by specifying

Attach: filename [description]

where filename is the file to attach and description is an optional string to use as the description of the attached file.

When replying to messages, if you remove the In-Reply-To: field from the header field, Mutt-ng will not generate a References: field, which allows you to create a new message thread.

Also see the and variables

#### Using Mutt-ng with PGP

If you want to use PGP, you can specify

Pgp: [E | S | S id]

``E'' encrypts, ``S'' signs and ``S<id>'' signs with the given key, setting permanently.

If you have told mutt to PGP encrypt a message, it will guide you through a key selection process when you try to send the message. Mutt-ng will not ask you any questions about keys which have a certified user ID matching one of the message recipients' mail addresses. However, there may be situations in which there are several keys, weakly certified user ID fields, or where no matching keys can be found.

In these cases, you are dropped into a menu with a list of keys from which you can select one. When you quit this menu, or mutt can't find any matching keys, you are prompted for a user ID. You can, as usually, abort this prompt using G. When you do so, mutt will return to the compose screen.

Once you have successfully finished the key selection, the message will be encrypted using the selected public keys, and sent out.

Most fields of the entries in the key selection menu (see also ) have obvious meanings. But some explanations on the capabilities, flags, and validity fields are in order.

The flags sequence (%f) will expand to one of the following flags:

##### PGP Key Menu Flags

Flag | Description
--- | ---
`R` | The key has been revoked and can't be used.
`X` | The key is expired and can't be used.
`d` | You have marked the key as disabled.
`c` | There are unknown critical self-signature packets.

The capabilities field (%c) expands to a two-character sequencerepresenting a key's capabilities. The first character gives the key's encryption capabilities: A minus sign ( - )means that the key cannot be used for encryption. A dot ( . )means that it's marked as a signature key in one of the user IDs, but may also be used for encryption. The letter e indicates that this key can be used for encryption.

The second character indicates the key's signing capabilities. Once again, a ``-'' implies ``not for signing'', ``.'' implies that the key is marked as an encryption key in one of the user-ids, and ``s'' denotes a key which can be used for signing.

Finally, the validity field (%t) indicates how well-certified a user-id is. A question mark (?) indicates undefined validity, a minus character (-) marks an untrusted association, a space character means a partially trusted association, and a plus character ( + ) indicates complete validity.

#### Sending anonymous messages via mixmaster

You may also have configured mutt to co-operate with Mixmaster, an anonymous remailer. Mixmaster permits you to send your messages anonymously using a chain of remailers. Mixmaster support in mutt is for mixmaster version 2.04 (beta 45 appears to be the latest) and 2.03. It does not support earlier versions or the later so-called version 3 betas, of which the latest appears to be called 2.9b23.

To use it, you'll have to obey certain restrictions. Most important, you cannot use the `Cc` and `Bcc` headers. To tell Mutt-ng to use mixmaster, you have to select a remailer chain, using the mix function on the compose menu.

The chain selection screen is divided into two parts. In the (larger) upper part, you get a list of remailers you may use. In the lower part, you see the currently selected chain of remailers.

You can navigate in the chain using the `chain-prev` and `chain-next` functions, which are by default bound to the left and right arrows and to the h and l keys (think vi keyboard bindings). To insert a remailer at the current chain position, use the `insert` function. To append a remailer behind the current chain position, use `select-entry` or `append` . You can also delete entries from the chain, using the corresponding function. Finally, to abandon your changes, leave the menu, or `accept` them pressing (by default) the `Return` key.

Note that different remailers do have different capabilities, indicated in the `%c` entry of the remailer menu lines (see ). Most important is the ``middleman'' capability, indicated by a capital ``M'': This means that the remailer in question cannot be used as the final element of a chain, but will only forward messages to other mixmaster remailers. For details on the other capabilities, please have a look at the mixmaster documentation.

### Forwarding and Bouncing Mail

Often, it is necessary to forward mails to other people. Therefore, mutt-ng supports forwarding messages in two different ways.

The first one is regular forwarding, as you probably know it from other mail clients. You simply press f, enter the recipient email address, the subject of the forwarded email, and then you can edit the message to be forwarded in the editor. The forwarded message is separated from the rest of the message via the two following markers:

----- Forwarded message from Lucas User <luser@example.com> ----- From: Lucas User <luser@example.com> Date: Thu, 02 Dec 2004 03:08:34 +0100 To: Michael Random <mrandom@example.com> Subject: Re: blackmail Pay me EUR 50,000.- cash or your favorite stuffed animal will die a horrible death. ----- End forwarded message -----

When you're done with editing the mail, save and quit the editor, and you will return to the compose menu, the same menu you also encounter when composing or replying to mails.

The second mode of forwarding emails with mutt-ng is the so-called bouncing: when you bounce an email to another address, it will be sent in practically the same format you send it (except for headers that are created during transporting the message). To bounce a message, press b and enter the recipient email address. By default, you are then asked whether you really want to bounce the message to the specified recipient. If you answer with yes, the message will then be bounced.

To the recipient, the bounced email will look as if he got it like a regular email where he was `Bcc:` recipient. The only possibility to find out whether it was a bounced email is to carefully study the email headers and to find out which host really sent the email.

### Postponing Mail

At times it is desirable to delay sending a message that you have already begun to compose. When the postpone-message function is used in the compose menu, the body of your message and attachments are stored in the mailbox specified by the variable. This means that you can recall the message even if you exit Mutt-ng and then restart it at a later time.

Once a message is postponed, there are several ways to resume it. From the command line you can use the ``-p'' option, or if you compose a new message from the index or pager you will be prompted if postponed messages exist. If multiple messages are currently postponed, the postponed menu will pop up and you can select which message you would like to resume.

Note: If you postpone a reply to a message, the reply setting of the message is only updated when you actually finish the message and send it. Also, you must be in the same folder with the message you replied to for the status of the message to be updated.

See also the quad-option.

## Configuration

### Locations of Configuration Files

While the default configuration (or ``preferences'') make Mutt-ng usable right out of the box, it is often desirable to tailor Mutt-ng to suit your own tastes. When Mutt-ng is first invoked, it will attempt to read the ``system'' configuration file (defaults set by your local system administrator), unless the ``-n'' commandline option is specified. This file is typically `/usr/local/share/muttng/Muttngrc` or `/etc/Muttngrc` , Mutt-ng users will find this file in `/usr/local/share/muttng/Muttrc` or `/etc/Muttngrc`. Mutt will next look for a file named `.muttrc` in your home directory, Mutt-ng will look for `.muttngrc`. If this file does not exist and your home directory has a subdirectory named `.mutt` , mutt try to load a file named `.muttng/muttngrc`.

`.muttrc` (or `.muttngrc` for Mutt-ng) is the file where you will usually place your commands to configure Mutt-ng.

### Basic Syntax of Initialization Files

An initialization file consists of a series of commands. Each line of the file may contain one or more commands. When multiple commands are used, they must be separated by a semicolon (;).

set realname='Mutt-ng user' ; ignore x-

The hash mark, or pound sign (``#''), is used as a ``comment'' character. You can use it to annotate your initialization file. All text after the comment character to the end of the line is ignored. For example,

my_hdr X-Disclaimer: Why are you listening to me? # This is a comment

Single quotes (') and double quotes (") can be used to quote strings which contain spaces or other special characters. The difference between the two types of quotes is similar to that of many popular shell programs, namely that a single quote is used to specify a literal string (one that is not interpreted for shell variables or quoting with a backslash (see next paragraph), while double quotes indicate a string for which should be evaluated. For example, backtics are evaluated inside of double quotes, but not for single quotes.

\ quotes the next character, just as in shells such as bash and zsh. For example, if want to put quotes ``"'' inside of a string, you can use ``\'' to force the next character to be a literal instead of interpreted character.

set realname="Michael \"MuttDude\" Elkins"

``\\'' means to insert a literal ``\'' into the line. ``\n'' and ``\r'' have their usual C meanings of linefeed and carriage-return, respectively.

A \ at the end of a line can be used to split commands over multiple lines, provided that the split points don't appear in the middle of command names.

Please note that, unlike the various shells, mutt-ng interprets a ``\'' at the end of a line also in comments. This allows you to disable a command split over multiple lines with only one ``#''.

# folder-hook . \ set realname="Michael \"MuttDude\" Elkins"

When testing your config files, beware the following caveat. The backslash at the end of the commented line extends the current line with the next line - then referred to as a ``continuation line''. As the first line is commented with a hash (#) all following continuation lines are also part of a comment and therefore are ignored, too. So take care of comments when continuation lines are involved within your setup files!

Abstract example:

line1\ line2a # line2b\ line3\ line4 line5

line1 ``continues'' until line4. however, the part after the # is a comment which includes line3 and line4. line5 is a new line of its own and thus is interpreted again.

The commands understood by mutt are explained in the next paragraphs. For a complete list, see the commands.

### Expansion within variables

Besides just assign static content to variables, there's plenty of ways of adding external and more or less dynamic content.

#### Commands' Output

It is possible to substitute the output of a Unix command in an initialization file. This is accomplished by enclosing the command in backquotes (``) as in, for example:

my_hdr X-Operating-System: `uname -a`

The output of the Unix command ``uname -a'' will be substituted before the line is parsed. Note that since initialization files are line oriented, only the first line of output from the Unix command will be substituted.

#### Environment Variables

UNIX environments can be accessed like the way it is done in shells like sh and bash: Prepend the name of the environment by a ``$'' sign. For example,

set record=+sent_on_$HOSTNAME

sets the variable to the string +sent_on_ and appends the value of the evironment variable .

Note: There will be no warning if an environment variable is not defined. The result will of the expansion will then be empty.

#### Configuration Variables

As for environment variables, the values of all configuration variables as string can be used in the same way, too. For example,

set imap_home_namespace = $folder

would set the value of to the value to which is currently set to.

Note: There're no logical links established in such cases so that the the value for won't change even if gets changed.

Note: There will be no warning if a configuration variable is not defined or is empty. The result will of the expansion will then be empty.

#### Self-Defined Variables

Mutt-ng flexibly allows users to define their own variables. To avoid conflicts with the standard set and to prevent misleading error messages, there's a reserved namespace for them: all user-defined variables must be prefixed with `user_` and can be used just like any ordinary configuration or environment variable.

For example, to view the manual, users can either define two macros like the following

macro generic <F1> "!less -r /path/to/manual" "Show manual" macro pager <F1> "!less -r /path/to/manual" "Show manual"

for `generic`, `pager` and `index` .The alternative is to define a custom variable like so:

set user_manualcmd = "!less -r /path/to_manual" macro generic <F1> "$user_manualcmd<enter>" "Show manual" macro pager <F1> "$user_manualcmd<enter>" "Show manual" macro index <F1> "$user_manualcmd<enter>" "Show manual"

to re-use the command sequence as in:

macro index <F2> "$user_manualcmd | grep '\^[ ]\\+~. '" "Show Patterns"

Using this feature, arbitrary sequences can be defined once and recalled and reused where necessary. More advanced scenarios could include to save a variable's value at the beginning of macro sequence and restore it at end.

When the variable is first defined, the first value it gets assigned is also the initial value to which it can be reset using the `reset` command.

The complete removal is done via the `unset` keyword.

After the following sequence:

set user_foo = 42 set user_foo = 666

the variable `$user_foo` has a current value of 666 and an initial of 42. The query

set ?user_foo

will show 666. After doing the reset via

reset user_foo

a following query will give 42 as the result. After unsetting it via

unset user_foo

any query or operation (except the noted expansion within other statements) will lead to an error message.

#### Pre-Defined Variables

In order to allow users to share one setup over a number of different machines without having to change its contents, there's a number of pre-defined variables. These are prefixed with `muttng_` and are read-only, i.e. they cannot be set, unset or reset. The reference chapter lists all available variables.

Please consult the local copy of your manual for their values as they may differ from different manual sources. Where the manual is installed in can be queried (already using such a variable) by running:

$ muttng -Q muttng_docdir

To extend the example for viewing the manual via self-defined variables, it can be made more readable and more portable by changing the real path in:

set user_manualcmd = '!less -r /path/to_manual'

to:

set user_manualcmd = "!less -r $muttng_docdir/manual.txt"

which works everywhere if a manual is installed.

Please note that by the type of quoting, muttng determines when to expand these values: when it finds double quotes, the value will be expanded during reading the setup files but when it finds single quotes, it'll expand it at runtime as needed.

For example, the statement

folder-hook . "set user_current_folder = $muttng_folder_name"

will be already be translated to the following when reading the startup files:

folder-hook . "set user_current_folder = some_folder"

with `some_folder` being the name of the first folder muttng opens. On the contrary,

folder-hook . 'set user_current_folder = $muttng_folder_name'

will be executed at runtime because of the single quotes so that `user_current_folder` will always have the value of the currently opened folder.

A more practical example is:

folder-hook . 'source ~/.mutt/score-$muttng_folder_name'

which can be used to source files containing score commands depending on the folder the user enters.

#### Type Conversions

A note about variable's types during conversion: internally values are stored in internal types but for any dump/query or set operation they're converted to and from string. That means that there's no need to worry about types when referencing any variable. As an example, the following can be used without harm (besides makeing muttng very likely behave strange):

set read_inc = 100 set folder = $read_inc set read_inc = $folder set user_magic_number = 42 set folder = $user_magic_number

### Defining/Using aliases

key address [, address,...]

It's usually very cumbersome to remember or type out the address of someone you are communicating with. Mutt-ng allows you to create ``aliases'' which map a short string to a full address.

Note: if you want to create an alias for a group (by specifying more than one address), you must separate the addresses with a comma (``,'').

To remove an alias or aliases (``*'' means all aliases):

[* | key ... ]

alias muttdude me@cs.hmc.edu (Michael Elkins) alias theguys manny, moe, jack

Unlike other mailers, Mutt-ng doesn't require aliases to be defined in a special file. The `alias` command can appear anywhere in a configuration file, as long as this file is . Consequently, you can have multiple alias files, or you can have all aliases defined in your muttrc.

On the other hand, the function can use only one file, the one pointed to by the variable (which is `~/.muttrc` by default). This file is not special either, in the sense that Mutt-ng will happily append aliases to any file, but in order for the new aliases to take effect you need to explicitly this file too.

For example:

source /usr/local/share/Mutt-ng.aliases source ~/.mail_aliases set alias_file=~/.mail_aliases

To use aliases, you merely use the alias at any place in mutt where muttprompts for addresses, such as the To: or Cc: prompt. You can also enter aliases in your editor at the appropriate headers if you have the variable set.

In addition, at the various address prompts, you can use the tab character to expand a partial alias to the full alias. If there are multiple matches, mutt will bring up a menu with the matching aliases. In order to be presented with the full list of aliases, you must hit tab with out a partial alias, such as at the beginning of the prompt or after a comma denoting multiple addresses.

In the alias menu, you can select as many aliases as you want with the select-entry key (default: RET), and use the exit key (default: q) to return to the address prompt.

### Changing the default key bindings

map key function

This command allows you to change the default key bindings (operation invoked when pressing a key).

map specifies in which menu the binding belongs. Multiple maps may be specified by separating them with commas (no additional whitespace isallowed). The currently defined maps are:

generic

  This is not a real menu, but is used as a fallback for all of the other menus except for the pager and editor modes. If a key is not defined in another menu, Mutt-ng will look for a binding to use in this menu. This allows you to bind a key to a certain function in multiple menus instead of having multiple bind statements to accomplish the same task.

alias

  The alias menu is the list of your personal aliases as defined in your muttrc. It is the mapping from a short alias name to the full email address(es) of the recipient(s).

attach

  The attachment menu is used to access the attachments on received messages.

browser

  The browser is used for both browsing the local directory structure, and for listing all of your incoming mailboxes.

editor

  The editor is the line-based editor the user enters text data.

index

  The index is the list of messages contained in a mailbox.

compose

  The compose menu is the screen used when sending a new message.

pager

  The pager is the mode used to display message/attachment data, and help listings.

pgp

  The pgp menu is used to select the OpenPGP keys used for encrypting outgoing messages.

postpone

  The postpone menu is similar to the index menu, except is used when recalling a message the user was composing, but saved until later.

key is the key (or key sequence) you wish to bind. To specify a control character, use the sequence \Cx, where x is the letter of the control character (for example, to specify control-A use ``\Ca''). Note that the case of x as well as \C is ignored, so that \CA, \Ca, \cA and \ca are all equivalent. An alternative form is to specify the key as a three digit octal number prefixed with a ``\'' (for example \177 is equivalent to \c?).

In addition, key may consist of:

#### Alternative Key Names

Sequence | Description
--- | ---
`\t` | tab
`<tab>` | tab
`<backtab>` | backtab / shift-tab
`\r` | carriage return
`\n` | newline
`\e` | escape
`<esc>` | escape
`<up>` | up arrow
`<down>` | down arrow
`<left>` | left arrow
`<right>` | right arrow
`<pageup>` | Page Up
`<pagedown>` | Page Down
`<backspace>` | Backspace
`<delete>` | Delete
`<insert>` | Insert
`<enter>` | Enter
`<return>` | Return
`<home>` | Home
`<end>` | End
`<space>` | Space bar
`<f1>` | function key 1
`<f10>` | function key 10

key does not need to be enclosed in quotes unless it contains a space (`` '').

function specifies which action to take when key is pressed. For a complete list of functions, see the functions. The special function `noop` unbinds the specified key sequence.

### Defining aliases for character sets

Usage: alias charset

Usage: charset local-charset

The command defines an alias for a character set. This is useful to properly display messages which are tagged with a character set name not known to mutt.

The command defines a system-specific name for a character set. This is helpful when your systems character conversion library insists on using strange, system-specific names for character sets.

### Setting variables based upon mailbox

Usage: [!]regexp command

It is often desirable to change settings based on which mailbox you are reading. The command provides a method by which you can execute any configuration command. regexp is a regular expression specifying in which mailboxes to execute command before loading. If a mailbox matches multiple 's, they are executed in the order given in the muttrc.

Note: if you use the ``!'' shortcut for at the beginning of the pattern, you must place it inside of double or single quotes in order to distinguish it from the logical not operator for the expression.

Note that the settings are not restored when you leave the mailbox. For example, a command action to perform is to change the sorting methodbased upon the mailbox being read:

folder-hook mutt set sort=threads

However, the sorting method is not restored to its previous value when reading a different mailbox. To specify a default command, use the pattern ``.'':

folder-hook . set sort=date-sent

### Keyboard macros

menu key sequence [description]

Macros are useful when you would like a single key to perform a series of actions. When you press key in menu menu ,Mutt-ng will behave as if you had typed sequence. So if you have a common sequence of commands you type, you can create a macro to execute those commands with a singlekey.

menu is the maps which the macro will be bound. Multiple maps may be specified by separating multiple menu arguments by commas. Whitespace may not be used in between the menu arguments and thecommas separating them.

key and sequence are expanded by the same rules as the . There are some additions however. The first is that control characters in sequence can also be specified as `^x`. In order to get a caret (`^'') you need to specify it twice. Secondly, to specify a certain key such as up or to invoke a function directly, you can use the format <key name> and <function name> .For a listing of key names see the section on . Functions are listed in the functions.

The advantage with using function names directly is that the macros willwork regardless of the current key bindings, so they are not dependent on the user having particular key definitions. This makes them more robustand portable, and also facilitates defining of macros in files used by more than one user (eg. the system Muttngrc).

Optionally you can specify a descriptive text after sequence, which is shown in the help screens.

Note: Macro definitions (if any) listed in the help screen(s), are silently truncated at the screen width, and are not wrapped.

### Using color and mono video attributes

object foreground background [regexp]

index foreground pattern

index pattern [pattern ...]

If your terminal supports color, you can spice up Mutt-ng by creating your own color scheme. To define the color of an object (type of information), you must specify both a foreground color and a background color (it is not possible to only specify one or the other).

object can be one of:

- attachment

- body (match regexp in the body of messages)

- bold (highlighting bold patterns in the body of messages)

- error (error messages printed by Mutt-ng)

- header (match regexp in the message header)

- hdrdefault (default color of the message header in the pager)

- index (match pattern in the message index)

- indicator (arrow or bar used to indicate the current item in a menu)

- markers (the ``+'' markers at the beginning of wrapped lines in the pager)

- message (informational messages)

- normal

- quoted (text matching in the body of a message)

- quoted1, quoted2, ..., quotedN (higher levels of quoting)

- search (highlighting of words in the pager)

- signature

- status (mode lines used to display info about the mailbox or message)

- tilde (the ``~'' used to pad blank lines in the pager)

- tree (thread tree drawn in the message index and attachment menu)

- underline (highlighting underlined patterns in the body of messages)

foreground and background can be one of the following:

- white

- black

- green

- magenta

- blue

- cyan

- yellow

- red

- default

- colorx

foreground can optionally be prefixed with the keyword `bright` to make the foreground color boldfaced (e.g., `brightred`).

If your terminal supports it, the special keyword default can be used as a transparent color. The value brightdefault is also valid. If Mutt-ng is linked against the S-Lang library, you also need to set the environment variable to the default colors of your terminal for this to work; for example (for Bourne-like shells):

set COLORFGBG="green;black" export COLORFGBG

Note: The S-Lang library requires you to use the lightgray and brown keywords instead of white and yellow when setting this variable.

Note: The uncolor command can be applied to the index object only. It removes entries from the list. You must specify the same pattern specified in the color command for it to be removed. The pattern ``*'' is a special token which means to clear the color index list of all entries.

Mutt-ng also recognizes the keywords color0, color1 ,..., colorN-1 ( N being the number of colors supported by your terminal). This is useful when you remap the colors for your display (for example by changing the color associated with color2 for your xterm), since color names may then lose their normal meaning.

If your terminal does not support color, it is still possible change the video attributes through the use of the ``mono'' command:

object attribute [regexp]

index attribute pattern

index pattern [pattern ...]

where attribute is one of the following:

- none

- bold

- underline

- reverse

- standout

### Ignoring (weeding) unwanted message headers

pattern [pattern ...]

pattern [pattern ...]

Messages often have many header fields added by automatic processing systems, or which may not seem useful to display on the screen. This command allows you to specify header fields which you don't normally want to see.

You do not need to specify the full header field name. For example, ``ignore content-'' will ignore all header fields that begin with the pattern ``content-''. ``ignore *'' will ignore all headers.

To remove a previously added token from the list, use the ``unignore'' command. The ``unignore'' command will make Mutt-ng display headers with the given pattern. For example, if you do ``ignore x-'' it is possible to ``unignore x-mailer''.

``unignore *'' will remove all tokens from the ignore list.

For example:

# Sven's draconian header weeding ignore * unignore from date subject to cc unignore organization organisation x-mailer: x-newsreader: x-mailing-list: unignore posted-to:

### Alternative addresses

regexp [regexp ...]

regexp [regexp ...]

With various functions, mutt will treat messages differently, depending on whether you sent them or whether you received them from someone else. For instance, when replying to a message that you sent to a different party, mutt will automatically suggest to send the response to the original message's recipients--responding to yourself won't make much sense in many cases. (See .)

Many users receive e-mail under a number of different addresses. To fully use mutt's features here, the program must be able to recognize what e-mail addresses you receive mail under. That's the purpose of the `alternates` command: It takes a list of regular expressions, each of which can identify an address under which you receive e-mail.

The `unalternates` command can be used to write exceptions to `alternates` patterns. If an address matches something in an `alternates` command, but you nonetheless do not think it is from you, you can list a more precise pattern under an `unalternates` command.

To remove a regular expression from the `alternates` list, use the `unalternates` command with exactly the same regexp . Likewise, if the regexp for a `alternates` command matches an entry on the `unalternates` list, that `unalternates` entry will be removed. If the regexp for `unalternates` is ``*'', all entries on `alternates` will be removed.

### Format = Flowed

#### Introduction

Mutt-ng contains support for so-called `format=flowed` messages. In the beginning of email, each message had a fixed line width, and it was enough for displaying them on fixed-size terminals. But times changed, and nowadays hardly anybody still uses fixed-size terminals: more people nowaydays use graphical user interfaces, with dynamically resizable windows. This led to the demand of a new email format that makes it possible for the email client to make the email look nice in a resizable window without breaking quoting levels and creating an incompatible email format that can also be displayed nicely on old fixed-size terminals.

For introductory information on `format=flowed` messages, see .

#### Receiving: Display Setup

When you receive emails that are marked as `format=flowed` messages, and is formatted correctly, mutt-ng will try to reformat the message to optimally fit on your terminal. If you want a fixed margin on the right side of your terminal, you can set the following:

set wrapmargin = 10

The code above makes the line break 10 columns before the right side of the terminal.

If your terminal is so wide that the lines are embarrassingly long, you can also set a maximum line length:

set max_line_length = 120

The example above will give you lines not longer than 120 characters.

When you view at `format=flowed` messages, you will often see the quoting hierarchy like in the following example:

>Bill, can you please send last month's progress report to Mr. >Morgan? We also urgently need the cost estimation for the new >production server that we want to set up before our customer's >project will go live.

This obviously doesn't look very nice, and it makes it very hard to differentiate between text and quoting character. The solution is to configure mutt-ng to "stuff" the quoting:

set stuff_quoted

This will lead to a nicer result that is easier to read:

> Bill, can you please send last month's progress report to Mr. > Morgan? We also urgently need the cost estimation for the new > production server that we want to set up before our customer's > project will go live.

#### Sending

If you want mutt-ng to send emails with `format=flowed` set, you need to explicitly set it:

set text_flowed

Additionally, you have to use an editor which supports writing `format=flowed`-conforming emails. For , this is done by adding `w` to the formatoptions (see `:h formatoptions` and `:h fo-table`) when writing emails.

Also note that format=flowed knows about ``space-stuffing'', that is, when sending messages, some kinds of lines have to be indented with a single space on the sending side. On the receiving side, the first space (if any) is removed. As a consequence and in addition to the above simple setting, please keep this in mind when making manual formattings within the editor. Also note that mutt-ng currently violates the standard () as it does not space-stuff lines starting with:

- `>` This is not the quote character but a right angle used for other reasons

Please make sure that you manually prepend a space to each of them.

#### Additional Notes

For completeness, the variable provides the mechanism to generate a `DelSp=yes` parameter on outgoing messages. According to the standard, clients receiving a `format=flowed` messages should delete the last space of a flowed line but still interpret the line as flowed. Because flowed lines usually contain only one space at the end, this parameter would make the receiving client concatenate the last word of the previous with the first of the current line without a space. This makes ordinary text unreadable and is intended for languages rarely using spaces. So please use this setting only if you're sure what you're doing.

### Mailing lists

regexp [regexp ...]

regexp [regexp ...]

regexp [regexp ...]

regexp [regexp ...]

Mutt-ng has a few nice features for using-lists. In order to take advantage of them, you must specify which addresses belong to mailing lists, and which mailing lists you are subscribed to. Once you have done this, the list-reply function will work for all known lists. Additionally, when you send a message to a subscribed list, mutt will add a Mail-Followup-To header to tell other users' mail user agents not to send copies of replies to your personal address. Note that the Mail-Followup-To header is a non-standard extension which is not supported by all mail user agents. Adding it is not bullet-proof against receiving personal CCs of list messages. Also note that the generation of the Mail-Followup-To header is controlled by the configuration variable.

More precisely, Mutt-ng maintains lists of patterns for the addresses of known and subscribed mailing lists. Every subscribed mailing list is known. To mark a mailing list as known, use the ``lists'' command. To mark it as subscribed, use ``subscribe''.

You can use regular expressions with both commands. To mark all messages sent to a specific bug report's address on mutt's bug tracking system as list mail, for instance, you could say ``subscribe [0-9]*@bugs.guug.de''. Often, it's sufficient to just give a portion of the list's e-mail address.

Specify as much of the address as you need to to remove ambiguity. For example, if you've subscribed to the Mutt-ng mailing list, you will receive mail addressed to mutt-users@mutt.org. So, to tell Mutt-ng that this is a mailing list, you could add ``lists mutt-users'' to your initialization file. To tell mutt that you are subscribed to it, add ``subscribe mutt-users'' to your initialization file instead. If you also happen to get mail from someone whose address is mutt-users@example.com, you could use ``lists mutt-users@mutt\\.org'' or ``subscribe mutt-users@mutt\\.org'' to match only mail from the actual list.

The ``unlists'' command is used to remove a token from the list of known and subscribed mailing-lists. Use ``unlists *'' to remove all tokens.

To remove a mailing list from the list of subscribed mailing lists, but keep it on the list of known mailing lists, use ``unsubscribe''.

### Using Multiple spool mailboxes

Usage: [!]pattern mailbox

This command is used to move read messages from a specified mailbox to adifferent mailbox automatically when you quit or change folders. pattern is a regular expression specifying the mailbox to treat as a ``spool'' mailbox and mailbox specifies where mail should be saved when read.

Unlike some of the other hook commands, only the first matching pattern is used (it is not possible to save read mail in more than a single mailbox).

### Defining mailboxes which receive mail

[!]filename [filename ... ]

[!]filename [filename ... ]

This command specifies folders which can receive mail and which will be checked for new messages. By default, the main menu status bar displays how many of these folders have new messages.

When changing folders, pressing space will cycle through folders with new mail.

Pressing TAB in the directory browser will bring up a menu showing the files specified by the `mailboxes` command, and indicate which contain new messages. Mutt-ng will automatically enter this mode when invoked from the command line with the `-y` option.

The ``unmailboxes'' command is used to remove a token from the list of folders which receive mail. Use ``unmailboxes *'' to remove all tokens.

Note: new mail is detected by comparing the last modification time to the last access time. Utilities like `biff` or `frm` or any other program which accesses the mailbox might cause Mutt-ng to never detect new mail for that mailbox if they do not properly reset the access time. Backup tools are another common reason for updated access times.

Note: the filenames in the `mailboxes` command are resolved when the command is executed, so if these names contain shortcuts (such as ``='' and ``!''), any variable definition that affect these characters (like and ) should be executed before the `mailboxes` command.

### User defined headers

string

field [field ...]

The ``my_hdr'' command allows you to create your own header fields which will be added to every message you send.

For example, if you would like to add an ``Organization:'' header field to all of your outgoing messages, you can put the command

my_hdr Organization: A Really Big Company, Anytown, USA

in your `.muttrc`.

Note: space characters are not allowed between the keyword and the colon (``:''). The standard for electronic mail () says that space is illegal there, so Mutt-ng enforces the rule.

If you would like to add a header field to a single message, you should either set the variable, or use the edit-headers function (default: ``E'') in the send-menu so that you can edit the header of your message along with the body.

To remove user defined header fields, use the ``unmy_hdr'' command. You may specify an asterisk (``*'') to remove all header fields, or the fields to remove. For example, to remove all ``To'' and ``Cc'' header fields, you could use:

unmy_hdr to cc

### Defining the order of headers when viewing messages

header header [header ...]

[ * | header header ...]

With this command, you can specify an order in which mutt will attempt to present headers to you when viewing messages.

``unhdr_order *'' will clear all previous headers from the order list, thus removing the header order effects set by the system-wide startup file.

hdr_order From Date: From: To: Cc: Subject:

### Specify default save filename

Usage: [!]pattern filename

This command is used to override the default filename used when saving messages. filename will be used as the default filename if the message is From: an address matching regexp or if you are the author and the message is addressed to: something matching regexp .

See for information on the exact format of pattern.

Examples:

save-hook me@(turing\\.)?cs\\.hmc\\.edu$ +elkins save-hook aol\\.com$ +spam

Also see the command.

### Specify default Fcc: mailbox when composing

Usage: [!]pattern mailbox

This command is used to save outgoing mail in a mailbox other than . Mutt-ng searches the initial list of message recipients for the first matching regexp and uses mailbox as the default Fcc: mailbox. If no match is found the message will be saved to mailbox.

See for information on the exact format of pattern.

Example:

fcc-hook [@.]aol\\.com$ +spammers

The above will save a copy of all messages going to the aol.com domain to the `+spammers' mailbox by default. Also see the command.

### Specify default save filename and default Fcc: mailbox at once

Usage: `` [!]pattern mailbox

This command is a shortcut, equivalent to doing both a and a with its arguments.

### Change settings based upon message recipients

Usage: [!]pattern command

Usage: [!]pattern command

Usage: [!]pattern command

These commands can be used to execute arbitrary configuration commands based upon recipients of the message. pattern is a regular expression matching the desired address. command is executed when regexp matches recipients of the message.

is matched against the message you are replying to, instead of the message you are sending . is matched against all messages, both new and replies .Note: s are matched before the , regardless of the order specified in the users's configuration file.

is matched every time a message is changed, either by editing it, or by using the compose menu to change its recipients or subject. is executed after ,and can, e.g., be used to set parameters such as the variable depending on the message's sender address.

For each type of or , when multiple matches occur, commands are executed in the order they are specified in the muttrc (for that type of hook).

See for information on the exact format of pattern.

Example: `send-hook mutt "set mime_forward signature=''"`

Another typical use for this command is to change the values of the , and variables in order to change the language of the attributions and signatures based upon the recipients.

Note: the 's are only executed ONCE after getting the initial list of recipients. Adding a recipient after replying or editing the message will NOT cause any to be executed. Also note that my_hdr commands which modify recipient headers, or the message's subject, don't have any effect on the current message when executed from a .

### Change settings before formatting a message

Usage: [!]pattern command

This command can be used to execute arbitrary configuration commands before viewing or formatting a message based upon information about the message. command is executed if the pattern matches the message to be displayed. When multiple matches occur, commands are executed in the order they are specified in the muttrc.

See for information on the exact format of pattern.

Example:

message-hook ~A 'set pager=builtin' message-hook '~f freshmeat-news' 'set pager="less \"+/^ subject:.*\""'

### Choosing the cryptographic key of the recipient

Usage: pattern keyid

When encrypting messages with PGP or OpenSSL, you may want to associate a certain key with a given e-mail address automatically, either because the recipient's public key can't be deduced from the destination address, or because, for some reasons, you need to override the key Mutt-ng wouldnormally use. The command provides a method by which you can specify the ID of the public key to be used when encrypting messages to a certain recipient.

The meaning of "key id" is to be taken broadly in this context: You can either put a numerical key ID here, an e-mail address, or even just a real name.

### Adding key sequences to the keyboard buffer

string

This command adds the named string to the keyboard buffer. The string may contain control characters, key names and function names like the sequence string in the command. You may use it to automatically run a sequence of commands at startup, or when entering certain folders. For example, the following command will automatically collapse all threads when entering a folder:

folder-hook . 'push <collapse-all>'

### Executing functions

function [function ... ]

This command can be used to execute any function. Functions are listed in the functions. ``exec function'' is equivalent to ``push <function>''.

### Message Scoring

pattern value

pattern [pattern ... ]

In situations where you have to cope with a lot of emails, e.g. when you read many different mailing lists, and take part in discussions, it is always useful to have the important messages marked and the annoying messages or the ones that you aren't interested in deleted. For this purpose, mutt-ng features a mechanism called ``scoring''.

When you use scoring, every message has a base score of 0. You can then use the `score` command to define patterns and a positive or negative value associated with it. When a pattern matches a message, the message's score will be raised or lowered by the amount of the value associated with the pattern.

score "~f nion@muttng\.org" 50 score "~f @sco\.com" -100

If the pattern matches, it is also possible to set the score value of the current message to a certain value and then stop evaluation:

score "~f santaclaus@northpole\.int" =666

What is important to note is that negative score values will be rounded up to 0.

To make scoring actually useful, the score must be applied in some way. That's what the score thresholds are for. Currently, there are three score thresholds:

- flag threshold: when a message has a score value equal or higher than the flag threshold, it will be flagged.

- read threshold: when a message has a score value equal or lower than the read threshold, it will be marked as read.

- delete threshold: when a message has a score value equal or lower than the delete threshold, it will be marked as deleted.

These three thresholds can be set via the variables , and .

By default, and are set to `-1`, which means that in the default threshold configuration no message will ever get marked as read or deleted.

Scoring gets especially interesting when combined with the `color` command and the pattern:

color index black yellow "~n 10-" color index red yellow "~n 100-"

The rules above mark all messages with a score between 10 and 99 with black and yellow, and messages with a score greater or equal 100 with red and yellow. This might be unusual to you if you're used to e.g. slrn's scoring mechanism, but it is more flexible, as it visually marks different scores.

### Spam detection

pattern format

pattern

Mutt-ng has generalized support for external spam-scoring filters. By defining your spam patterns with the `spam` and `nospam` commands, you can limit, search, and sort your mail based on its spam attributes, as determined by the external filter. You also can display the spam attributes in your index display using the `%H` selector in the variable. (Tip: try `%?H?[%H] ?` to display spam tags only when they are defined for a given message.)

Your first step is to define your external filter's spam patterns using the `spam` command. pattern should be a regular expression that matches a header in a mail message. If any message in the mailbox matches this regular expression, it will receive a ``spam tag'' or ``spam attribute'' (unless it also matches a `nospam` pattern -- see below.) The appearance of this attribute is entirely up to you, and is governed by the format parameter. format can be any static text, but it also can include back-references from the pattern expression. (A regular expression ``back-reference'' refers to a sub-expression contained within parentheses.) `%1` is replaced with the first back-reference in the regex, `%2` with the second, etc.

If you're using multiple spam filters, a message can have more than one spam-related header. You can define `spam` patterns for each filter you use. If a message matches two or more of these patterns, and the $spam_separator variable is set to a string, then the message's spam tag will consist of all the format strings joined together, with the value of $spam_separator separating them.

For example, suppose I use DCC, SpamAssassin, and PureMessage. I might define these spam settings:

spam "X-DCC-.*-Metrics:.*(....)=many" "90+/DCC-%1" spam "X-Spam-Status: Yes" "90+/SA" spam "X-PerlMX-Spam: .*Probability=([0-9]+)%" "%1/PM" set spam_separator=", "

If I then received a message that DCC registered with ``many'' hits under the ``Fuz2'' checksum, and that PureMessage registered with a 97% probability of being spam, that message's spam tag would read`90+/DCC-Fuz2, 97/PM`. (The four characters before ``=many'' in a DCC report indicate the checksum used -- in this case, ``Fuz2''.)

If the $spam_separator variable is unset, then each spam pattern match supersedes the previous one. Instead of getting joined format strings, you'll get only the last one to match.

The spam tag is what will be displayed in the index when you use `%H` in the `$index_format` variable. It's also the string that the pattern-matching expression matches against for search and limit functions. And it's what sorting by spam attribute will use as a sort key.

That's a pretty complicated example, and most people's actual environments will have only one spam filter. The simpler your configuration, the more effective mutt can be, especially when it comes to sorting.

Generally, when you sort by spam tag, mutt will sort lexically -- that is, by ordering strings alphnumerically. However, if a spam tag begins with a number, mutt will sort numerically first, and lexically only when two numbers are equal in value. (This is like UNIX's `sort -n`.) A message with no spam attributes at all -- that is, one that didn't match any of your `spam` patterns -- is sorted at lowest priority. Numbers are sorted next, beginning with 0 and ranging upward. Finally, non-numeric strings are sorted, with ``a'' taking lowerpriority than ``z''. Clearly, in general, sorting by spam tags is most effective when you can coerce your filter to give you a raw number. But in case you can't, mutt can still do something useful.

The `nospam` command can be used to write exceptions to `spam` patterns. If a header pattern matches something in a `spam` command, but you nonetheless do not want it to receive a spam tag, you can list amore precise pattern under a `nospam` command.

If the pattern given to `nospam` is exactly the same as the pattern on an existing `spam` list entry, the effect will be to remove the entry from the spam list, instead of adding an exception. Likewise, if the pattern for a `spam` command matches an entry on the `nospam` list, that `nospam` entry will be removed. If the pattern for `nospam` is ``*'', all entries on both lists will be removed. This might be the default action if you use `spam` and `nospam` in conjunction with a .

You can have as many `spam` or `nospam` commands as you like. You can even do your own primitive spam detection within mutt -- for example, if you consider all mail from `MAILER-DAEMON` to be spam, you can use a `spam` command like this:

spam "^From: .*MAILER-DAEMON" "999"

### Setting variables

[no|inv]variable [=value] [variable...]

variable [variable ...]

variable [variable ...]

variable [variable ...]

This command is used to set (and unset) variables. There are four basic types of variables: boolean, number, string and quadoption. boolean variables can be set (true) or unset (false). number variables can be assigned a positive integer value.

string variables consist of any number of printable characters. strings must be enclosed in quotes if they contain spaces or tabs. You may also use the ``C'' escape sequences \n and \t for newline and tab, respectively.

quadoption variables are used to control whether or not to be prompted for certain actions, or to specify a default action. A value of yes will cause the action to be carried out automatically as if you had answered yes to the question. Similarly, a value of no will cause the the action to be carried out as if you had answered ``no.'' A value of ask-yes will cause a prompt with a default answer of ``yes'' and ask-no will provide a default answer of ``no.''

Prefixing a variable with ``no'' will unset it. Example: `set noaskbcc` .

For boolean variables, you may optionally prefix the variable name with `inv` to toggle the value (on or off). This is useful when writing macros. Example: `set invsmart_wrap`.

The `toggle` command automatically prepends the `inv` prefix to all specified variables.

The `unset` command automatically prepends the `no` prefix to all specified variables.

Using the enter-command function in the index menu, you can query the value of a variable by prefixing the name of the variable with a question mark:

set ?allow_8bit

The question mark is actually only required for boolean and quadoption variables.

The `reset` command resets all given variables to the compile time defaults (hopefully mentioned in this manual). If you use the command `set` and prefix the variable with ``&'' this has the same behavior as the reset command.

With the `reset` command there exists the special variable ``all'', which allows you to reset all variables to their system defaults.

### Reading initialization commands from another file

filename [filename ...]

This command allows the inclusion of initialization commands from other files. For example, I place all of my aliases in `~/.mail_aliases` so that I can make my `~/.muttrc` readable and keep my aliases private.

If the filename begins with a tilde (``~''), it will be expanded to the path of your home directory.

If the filename ends with a vertical bar (|), then filename is considered to be an executable program from which to read input (eg. `source ~/bin/myscript|`).

### Removing hooks

[* | hook-type]

This command permits you to flush hooks you have previously defined. You can either remove all hooks by giving the ``*'' character as an argument, or you can remove all hooks of a specific type by saying something like `unhook send`.

### Sharing Setups

#### Character Sets

As users may run mutt-ng on different systems, the configuration must be maintained because it's likely that people want to use the setup everywhere they use mutt-ng. And mutt-ng tries to help where it can.

To not produce conflicts with different character sets, mutt-ng allows users to specify in which character set their configuration files are encoded. Please note that while reading the configuration files, this is only respected after the corresponding declaration appears. It's advised to put the following at the very beginning of a users muttngrc:

set config_charset = "..."

and replacing the dots with the actual character set. To avoid problems while maintaining the setup, user's may want to use modelines as show in:

    # vim:fileencoding=...:

while, again, replacing the dots with the appropriate name. This tells as which character set to read and save the file.

#### Modularization

``Modularization'' means to divide the setup into several files while sorting the options or commands by topic. Especially for longer setups (e.g. with many hooks), this helps maintaining it and solving trouble.

When using separation, setups may be, as a whole or in fractions, shared over different systems.

#### Conditional parts

When using a configuration on different systems, the user may not always have influence on how mutt-ng is installed and which features it includes.

To solve this, mutt-ng contain a feature based on the ``ifdef'' patch written for mutt. Its basic syntax is:

ifdef <item> <command> ifndef <item> <command>

...whereby `<item>` can be one of:

- a function name

- a variable name

- a menu name

- a feature name

All available functions, variables and menus are documented elsewhere in this manual but ``features'' is specific to these two commands. To test for one, prefix one of the following keywords with `feature_`: ncurses, slang, iconv, idn, dotlock, standalone, pop, nntp, imap, ssl, gnutls, sasl, sasl2, libesmtp, compressed, color, classic_pgp, classic_smime, gpgme, header_cache

As an example, one can use the following in `~/.muttngrc`:

ifdef feature_imap 'source ~/.mutt-ng/setup-imap' ifdef feature_pop 'source ~/.mutt-ng/setup-pop' ifdef feature_nntp 'source ~/.mutt-ng/setup-nntp'

...to only source `~/.mutt-ng/setup-imap` if IMAP support is built in, only source `~/.mutt-ng/setup-pop` if POP support is built in and only source `~/.mutt-ng/setup-nntp` if NNTP support is built in.

An example for testing for variable names can be used if users use different revisions of mutt-ng whereby the older one may not have a certain variable. To test for the availability of use:

ifdef imap_mail_check 'set imap_mail_check = 300'

Provided for completeness is the test for menu names. To set only if the pager menu is available, use:

ifdef pager 'set pager_index_lines = 10'

For completeness, too, the opposite of `ifdef` is provided: `ifndef` which only executes the command if the test fails. For example, the following two examples are equivalent:

ifdef feature_ncurses 'source ~/.mutt-ng/setup-ncurses' ifndef feature_ncurses 'source ~/.mutt-ng/setup-slang'

...and...

ifdef feature_slang 'source ~/.mutt-ng/setup-slang' ifndef feature_slang 'source ~/.mutt-ng/setup-ncurses'

### Obsolete Variables

In the process of ensuring and creating more consistency, many variables have been renamed and some of the old names were already removed. Please see sect-obsolete for a complete list.

## Advanced Usage

### Regular Expressions

All string patterns in Mutt-ng including those in more complex patterns must be specified using regular expressions (regexp) in the ``POSIX extended'' syntax (which is more or less the syntax used by egrep and GNU awk). For your convenience, we have included below a brief description of this syntax.

The search is case sensitive if the pattern contains at least one upper case letter, and case insensitive otherwise. Note that ``\'' must be quoted if used for a regular expression in an initialization command: ``\\''.

A regular expression is a pattern that describes a set of strings. Regular expressions are constructed analogously to arithmetic expressions, by using various operators to combine smaller expressions.

Note that the regular expression can be enclosed/delimited by either " or ' which is useful if the regular expression includes a white-space character. See muttrc-syntax for more information on " and ' delimiter processing. To match a literal " or ' you must preface it with \ (backslash).

The fundamental building blocks are the regular expressions that match a single character. Most characters, including all letters and digits, are regular expressions that match themselves. Any metacharacter with special meaning may be quoted by preceding it with a backslash.

The period ``.'' matches any single character. The caret ``^'' andthe dollar sign ``$'' are metacharacters that respectively match the empty string at the beginning and end of a line.

A list of characters enclosed by ``]'' and ``]'' matches any single character in that list; if the first character of the list is a caret ``^'' then it matches any character not in the list. For example, the regular expression ]0123456789] matches any single digit. A range of ASCII characters may be specified by giving the first and last characters, separated by a hyphen ``-''. Most metacharacters lose their special meaning inside lists. To include a literal ``]'' place it first in the list. Similarly, to include a literal ``^'' place it anywhere but first. Finally, to include a literal hyphen ``-'' place it last.

Certain named classes of characters are predefined. Character classes consist of ``[:'', a keyword denoting the class, and ``:]''. The following classes are defined by the POSIX standard:

[:alnum:]

  Alphanumeric characters.

[:alpha:]

  Alphabetic characters.

[:blank:]

  Space or tab characters.

[:cntrl:]

  Control characters.

[:digit:]

  Numeric characters.

[:graph:]

  Characters that are both printable and visible. (A space is printable, but not visible, while an ``a'' is both.)

[:lower:]

  Lower-case alphabetic characters.

[:print:]

  Printable characters (characters that are not control characters.)

[:punct:]

  Punctuation characters (characters that are not letter, digits, control characters, or space characters).

[:space:]

  Space characters (such as space, tab and formfeed, to name a few).

[:upper:]

  Upper-case alphabetic characters.

[:xdigit:]

  Characters that are hexadecimal digits.

A character class is only valid in a regular expression inside the brackets of a character list. Note that the brackets in these class names are part of the symbolic names, and must be included in addition to the brackets delimiting the bracket list. For example, [[:digit:]] is equivalent to [0-9].

Two additional special sequences can appear in character lists. These apply to non-ASCII character sets, which can have single symbols (calledcollating elements) that are represented with more than one character, as well as several characters that are equivalent for collating or sorting purposes:

Collating Symbols

  A collating symbol is a multi-character collating element enclosed in ``[.'' and ``.]''. For example, if ``ch'' is a collating element, then [[.ch.]] is a regexp that matches this collating element, while [ch] is a regexp that matches either ``c'' or ``h''.

Equivalence Classes

  An equivalence class is a locale-specific name for a list of characters that are equivalent. The name is enclosed in ``[='' and ``=]''. For example, the name ``e'' might be used to represent all of ``è'' ``é'' and ``e''. In this case, [[=e=]] is a regexp that matches any of ``è'', ``é'' and ``e''.

A regular expression matching a single character may be followed by one of several repetition operators:

?

  The preceding item is optional and matched at most once.

*

  The preceding item will be matched zero or more times.

+

  The preceding item will be matched one or more times.

{n}

  The preceding item is matched exactly n times.

{n,}

  The preceding item is matched n or more times.

{,m}

  The preceding item is matched at most m times.

{n,m}

  The preceding item is matched at least n times, but no more than m times.

Two regular expressions may be concatenated; the resulting regular expression matches any string formed by concatenating two substrings that respectively match the concatenated subexpressions.

Two regular expressions may be joined by the infix operator ``|''; the resulting regular expression matches any string matching either subexpression.

Repetition takes precedence over concatenation, which in turn takes precedence over alternation. A whole subexpression may be enclosed in parentheses to override these precedence rules.

Note: If you compile Mutt-ng with the GNU rx package, the following operators may also be used in regular expressions:

\\y

  Matches the empty string at either the beginning or the end of a word.

\\B

  Matches the empty string within a word.

\\<

  Matches the empty string at the beginning of a word.

\\>

  Matches the empty string at the end of a word.

\\w

  Matches any word-constituent character (letter, digit, or underscore).

\\W

  Matches any character that is not word-constituent.

\\`

  Matches the empty string at the beginning of a buffer (string).

\\'

  Matches the empty string at the end of a buffer.

Please note however that these operators are not defined by POSIX, so they may or may not be available in stock libraries on various systems.

### Patterns

Mutt-ng's pattern language provides a simple yet effective way to set up rules to match messages, e.g. for operations like tagging and scoring. A pattern consists of one or more sub-pattern, which can be logically grouped, ORed, and negated. For a complete listing of these patterns, please refer to table patterns in the Reference chapter.

It must be noted that in this table, `EXPR` is a regular expression. For ranges, the forms `<[MAX]`, `>>[MIN]`, `[MIN]-` and `-[MAX]` are also possible.

#### Complex Patterns

It is possible to combine several sub-patterns to a more complex pattern. The most simple possibility is to logically AND several patterns by stringing them together:

     'SPAM'

The pattern above matches all messages that contain ``SPAM'' in the subject and are unread.

To logical OR patterns, simply use the `|` operator. This one especially useful when using local groups:

     ("nion@muttng\.org"|"ak@muttng\.org"|"pdmef@muttng\.org")
    ( mutt-ng| Mutt-ng)
    ! '@synflood\.at'

The first pattern matches all messages that were sent by one of the mutt-ng maintainers, while the seconds pattern matches all messages that contain ``mutt-ng'' in the message body or ``Mutt-ng'' in the subject. The third pattern matches all messages that do not contain ``@synflood\.at'' in the `References:` header, i.e. messages that are not an (indirect) reply to one of my messages. A pattern can be logicall negated using the `!` operator.

#### Patterns and Dates

When using dates in patterns, the dates must be specified in a special format, i.e. `DD/MM/YYYY`. If you don't specify month or year, they default to the current month or year. When using date ranges, and you specify only the minimum or the maximum, the specified date will be excluded, e.g. `01/06/2005-` matches against all messages after Juni 1st, 2005.

It is also possible to use so-called ``error margins'' when specifying date ranges. You simply specify a date, and then the error margin. This margin needs to contain the information whether it goes ``forth'' or ``back'' in time, by using `+` and `-`. Then follows a number and a unit, i.e. `y` for years, `m` for months, `w` for weeks and `d` for days. If you use the special `*` sign, it means that the error margin goes to both``directions'' in time.

     01/01/2005+1y
     18/10/2004-2w
     28/12/2004*1d

The first pattern matches all dates between January 1st, 2005 and January 1st 2006. The second pattern matches all dates between October 18th, 2004 and October 4th 2004 (2 weeks before 18/10/2004), while the third pattern matches all dates 1 day around December 28th, 2004 (i.e. Dec 27th, 28th and 29th).

Relative dates are also very important, as they make it possible to specify date ranges between a fixed number of units and the current date. How this works can be seen in the following example:

     >2w # messages older than two weeks
     <3d # messages newer than 3 days
     =1m # messages that are exactly one month old

### Format Strings

#### Introduction

The so called Format Strings offer great flexibility when configuring mutt-ng. In short, they describe what items to print out how in menus and status messages.

Basically, they work as this: for different menus and bars, there's a variable specifying the layout. For every item available, there is a so called expando.

For example, when running mutt-ng on different machines or different versions for testing purposes, it may be interesting to have the following information always printed on screen when one is in the index:

- the current hostname

- the current mutt-ng version number

The setting for the status bar of the index is controlled via the variable. For the hostname and version string, there's an expando for `$status_format`: `%h` expands to the hostname and `%v` to the version string. When just configuring:

set status_format = "%v on %h: ..."

mutt-ng will replace the sequence `%v` with the version string and `%h` with the host's name. When you are, for example, running mutt-ng version `1.5.9i` on host `mailhost`, you'll see the following when you're in the index:

    Mutt-ng 1.5.9i on mailhost: ...

In the index, there're more useful information one could want to see:

- which mailbox is open

- how man new, flagged or postponed messages

- ...

To include the mailbox' name is as easy as:

set status_format = "%v on %h: %B: ...

When the currently opened mailbox is `Inbox`, this will be expanded to:

    Mutt-ng 1.5.9i on mailhost: Inbox: ...

For the number of certain types of messages, one more feature of the format strings is extremely useful. If there aren't messages of a certain type, it may not be desired to print just that there aren't any but instead only print something if there are any.

#### Conditional Expansion

To only print the number of messages if there are new messages in the current mailbox, further extend `$status_format` to:

set status_format = "%v on %h: %B %?n?%n new? ...

This feature is called nonzero-printing and works as this: some expandos may be optionally printed nonzero, i.e. a portion of the format string is only evaluated if the value of the expando is different from zero. The basic syntax is:

    %?<item>?<string if nonzero>?

which tells mutt-ng to only look at `<string if nonzero>` if the value of the `%<item%gt;` expando is different from zero. In our example, we used `n` as the expando to check for and `%n new` as the optional nonzero string.

But this is not all: this feature only offers one alternative: ``print something if not zero.'' Mutt-ng does, as you might guess, also provide a logically complete version: ``if zero, print something and else print something else.'' This is achieved by the following syntax for those expandos which may be printed nonzero:

    %?<item>?<string if nonzero>&<string if zero>?

Using this we can make mutt-ng to do the following:

- make it print ``n new messages'' whereby n is the count but only if there new ones

- and make it print ``no new messages'' if there aren't any

The corresponding configuration is:

set status_format = "%v on %h: %B: %?n?%n new messages&no new messages? ...

This doubles the use of the ``new messages'' string because it'll get always printed. Thus, it can be shortened to:

set status_format = "%v on %h: %B: %?n?%n&no? new messages ...

As you might see from this rather simple example, one can create very complex but fancy status messages. Please see the reference chapter for expandos and those which may be printed nonzero.

#### Modifications and Padding

Besides the information given so far, there're even more features of format strings:

- When specifying `%_<item>` instead of just `%<item>`, mutt-ng will convert all characters in the expansion of `<item>` to lowercase.

- When specifying `%:<item>` instead of just `%<item>`, mutt-ng will convert all dots in the expansion of `<item>` to underscores (`_`).

Also, there's a feature called Padding supplied by the following two expandos: `%|X` and `%>X` .

`%|X`

  When this occurs, mutt-ng will fill the rest of the line with the character `X`. In our example, filling the rest of the line with dashes is done by setting:

  set status_format = "%v on %h: %B: %?n?%n&no? new messages %|-"

`%>X`

  Since the previous expando stops at the end of line, there must be a way to fill the gap between two items via the `%>X` expando: it puts as many characters `X` in between two items so that the rest of the line will be right-justified. For example, to not put the version string and hostname of our example on the left but on the right and fill the gap with spaces, one might use (note the space after `%>`):

  set status_format = "%B: %?n?%n&no? new messages %> (%v on %h)"

### Using Tags

Sometimes it is desirable to perform an operation on a group of messages all at once rather than one at a time. An example might be to save messages to a mailing list to a separate folder, or to delete all messages with a given subject. To tag all messages matching a pattern, use the tag-pattern function, which is bound to ``shift-T'' by default. Or you can select individual messages by hand using the ``tag-message'' function, which is bound to ``t'' by default. See patterns for Mutt-ng's pattern matching syntax.

Once you have tagged the desired messages, you can use the ``tag-prefix'' operator, which is the ``;'' (semicolon) key by default. When the ``tag-prefix'' operator is used, the next operation will be applied to all tagged messages if that operation can be used in that manner. If the variable is set, the next operation applies to the tagged messages automatically, without requiring the ``tag-prefix''.

In or commands, you can use the ``tag-prefix-cond'' operator. If there are no tagged messages, mutt will "eat" the rest of the macro to abort it's execution.Mutt-ng will stop "eating" the macro when it encounters the ``end-cond'' operator; after this operator the rest of the macro will be executed asnormal.

### Using Hooks

A hook is a concept borrowed from the EMACS editor which allows you to execute arbitrary commands before performing some operation. For example, you may wish to tailor your configuration based upon which mailbox you are reading, or to whom you are sending mail. In the Mutt-ng world, a hook consists of a regexp or patterns along with a configuration option/command. See

for specific details on each type of hook available.

Note: if a hook changes configuration settings, these changes remain effective until the end of the current mutt session. As this is generally not desired, a default hook needs to be added before all other hooks to restore configuration defaults. Here is an example with and the my_hdr directive:

send-hook . 'unmy_hdr From:' send-hook '~C ^b@b\.b$' my-hdr from: c@c.c

#### Message Matching in Hooks

Hooks that act upon messages (`, , ,` )are evaluated in a slightly different manner. For the other types of hooks, a regexp is sufficient. But in dealing with messages a finer grain of control is needed for matching since for different purposes you want to match different criteria.

Mutt-ng allows the use of the patterns language for matching messages in hook commands. This works in exactly the same way as it would when limiting orsearching the mailbox, except that you are restricted to those operators which match information mutt extracts from the header of the message (i.e. from, to, cc, date, subject, etc.).

For example, if you wanted to set your return address based upon sending mail to a specific address, you could do something like:

send-hook '~t ^me@cs\.hmc\.edu$' 'my-hdr From: Mutt-ng User <user@host>'

which would execute the given command when sending mail to me@cs.hmc.edu.

However, it is not required that you write the pattern to match using the full searching language. You can still specify a simple regular expression like the other hooks, in which case Mutt-ng will translate your pattern into the full language, using the translation specified by the variable. The pattern is translated at the time the hook is declared, so the value of that is in effect at that time will be used.

### Using the sidebar

The sidebar, a feature specific to Mutt-ng, allows you to use a mailbox listing which looks very similar to the ones you probably know from GUI mail clients. The sidebar lists all specified mailboxes, shows the number in each and highlights the ones with new email Use the following configuration commands:

set sidebar_visible="yes" set sidebar_width=25

If you want to specify the mailboxes you can do so with:

set mbox='=INBOX' mailboxes INBOX \ MBOX1 \ MBOX2 \ ...

You can also specify the colors for mailboxes with new mails by using:

color sidebar_new red black color sidebar white black

Reasonable key bindings look e.g. like this:

bind index \Cp sidebar-prev bind index \Cn sidebar-next bind index \Cb sidebar-open bind pager \Cp sidebar-prev bind pager \Cn sidebar-next bind pager \Cb sidebar-open macro index B ':toggle sidebar_visible^M' macro pager B ':toggle sidebar_visible^M'

You can then go up and down by pressing Ctrl-P and Ctrl-N, and switch on and off the sidebar simply by pressing 'B'.

### External Address Queries

Mutt-ng supports connecting to external directory databases such as LDAP, ph/qi, bbdb, or NIS through a wrapper script which connects to mutt using a simple interface. Using the variable, you specify the wrapper command to use. For example:

set query_command = "mutt_ldap_query.pl '%s'"

The wrapper script should accept the query on the command-line. It should return a one line message, then each matching response on a single line, each line containing a tab separated address then name thensome other optional information. On error, or if there are no matching addresses, return a non-zero exit code and a one line error message.

An example multiple response output:

    Searching database ... 20 entries ... 3 matching:
    me@cs.hmc.edu           Michael Elkins  mutt dude
    blong@fiction.net       Brandon Long    mutt and more
    roessler@guug.de        Thomas Roessler mutt pgp

There are two mechanisms for accessing the query function of mutt. One is to do a query from the index menu using the query function (default: Q). This will prompt for a query, then bring up the query menu which will list the matching responses. From the query menu, you can select addresses to create aliases, or to mail. You can tag multiple addressesto mail, start a new query, or have a new query appended to the current responses.

The other mechanism for accessing the query function is for address completion, similar to the alias completion. In any prompt for address entry, you can use the complete-query function (default: ^T) to run a query based on the current address you have typed. Like aliases, mutt will look for what you have typed back to the last space or comma. If there is a single response for that query, mutt will expand the address in place. If there are multiple responses, mutt will activate the querymenu. At the query menu, you can select one or more addresses to be added to the prompt.

### Mailbox Formats

Mutt-ng supports reading and writing of four different mailbox formats: mbox, MMDF, MH and Maildir. The mailbox type is autodetected, so there is no need to use a flag for different mailbox types. When creating newmailboxes, Mutt-ng uses the default specified with the variable.

mbox. This is the most widely used mailbox format for UNIX. All messages are stored in a single file. Each message has a line of the form:

From me@cs.hmc.edu Fri, 11 Apr 1997 11:44:56 PST

to denote the start of a new message (this is often referred to as the ``From_'' line).

MMDF. This is a variant of the mbox format. Each message is surrounded by lines containing ``^A^A^A^A'' (four control-A's).

MH. A radical departure from mbox and MMDF, a mailbox consists of a directory and each message is stored in a separate file. The filename indicates the message number (however, this is may not correspond to the message number Mutt-ng displays). Deleted messages arerenamed with a comma (,) prepended to the filename. Note: Mutt detects this type of mailbox by looking for either `.mh_sequences` or `.xmhcache` (needed to distinguish normal directories from MH mailboxes).

Maildir. The newest of the mailbox formats, used by the Qmail MTA (a replacement for sendmail). Similar to MH, except that it adds three subdirectories of the mailbox: tmp, new and cur .Filenames for the messages are chosen in such a way they are unique, even when twoprograms are writing the mailbox over NFS, which means that no file locking is needed.

### Mailbox Shortcuts

There are a number of built in shortcuts which refer to specific mailboxes. These shortcuts can be used anywhere you are prompted for a file or mailbox path.

- ! -- refers to your (incoming) mailbox

- > -- refers to your file

- < -- refers to your file

- ^ -- refers to the current mailbox

- - or !! -- refers to the file you've last visited

- ~ -- refers to your home directory

- = or + -- refers to your directory

- @alias -- refers to the as determined by the address of the alias

### Handling Mailing Lists

Mutt-ng has a few configuration options that make dealing with large amounts of mail easier. The first thing you must do is to let Mutt know what addresses you consider to be mailing lists (technically this does not have to be a mailing list, but that is what it is most often used for), and what lists you are subscribed to. This is accomplished through the use of the commands in your muttrc.

Now that Mutt-ng knows what your mailing lists are, it can do several things, the first of which is the ability to show the name of a list through which you received a message (i.e., of a subscribed list) in the index menu display. This is useful to distinguish between personal and list mail in the same mailbox. In the variable, the escape ``%L'' will return the string ``To <list>'' when ``list'' appears in the ``To'' field, and ``Cc <list>'' when it appears in the ``Cc'' field (otherwise it returns the name of the author).

Often times the ``To'' and ``Cc'' fields in mailing list messages tend to get quite large. Most people do not bother to remove the author of the message they are reply to from the list, resulting in two or more copies being sent to that person. The ``list-reply'' function, which by default is bound to ``L'' in the index menu and pager, helps reduce the clutter by only replying to the known mailing list addresses instead of all recipients (except as specified by `Mail-Followup-To`, see below).

Mutt-ng also supports the `Mail-Followup-To` header. When you send a message to a list of recipients which includes one or several subscribed mailing lists, and if the option is set, mutt will generate a Mail-Followup-To header which contains all the recipients to whom you send this message, but not your address. This indicates that group-replies or list-replies (also known as ``followups'') to this message should only be sent to the original recipients of the message, and not separately to you - you'll receive your copy through one of the mailing lists you are subscribed to.

Conversely, when group-replying or list-replying to a message which has a `Mail-Followup-To` header, mutt will respect this header if the configuration variable is set. Using list-reply will in this case also make sure that the reply goes to the mailing list, even if it's not specified in the list of recipients in the `Mail-Followup-To`.

Note that, when header editing is enabled, you can create a `Mail-Followup-To` header manually. Mutt-ng will only auto-generate this header if it doesn't exist when you send the message.

The other method some mailing list admins use is to generate a ``Reply-To'' field which points back to the mailing list address rather than the author of the message. This can create problems when trying to reply directly to the author in private, since most mail clients will automatically reply to the address given in the ``Reply-To'' field. Mutt-ng uses the variable to help decide which address to use. If set to ask-yes or ask-no, you will be prompted as to whether or not you would like to use the address given inthe ``Reply-To'' field, or reply directly to the address given in the ``From'' field. When set to yes, the ``Reply-To'' field will be used when present.

The ``X-Label:'' header field can be used to further identify mailing lists or list subject matter (or just to annotate messages individually). The variable's ``%y'' and ``%Y'' escapes can be used to expand ``X-Label:'' fields in the index, and Mutt-ng's pattern-matcher can match regular expressions to ``X-Label:'' fields with the ``'' selector. ``X-Label:'' is not a standard message header field, but it can easily be inserted by procmailand other mail filtering agents.

Lastly, Mutt-ng has the ability to sort the mailbox into threads. A thread is a group of messages which all relate to the same subject. This is usually organized into a tree-like structure where a message and all of its replies are represented graphically. If you've ever used a threaded news client, this is the same concept. It makes dealingwith large volume mailing lists easier because you can easily delete uninteresting threads and quickly find topics of value.

### Editing threads

Mutt-ng has the ability to dynamically restructure threads that are broken either by misconfigured software or bad behavior from some correspondents. This allows to clean your mailboxes formats) from these annoyances which make it hard to follow a discussion.

#### Linking threads

Some mailers tend to "forget" to correctly set the "In-Reply-To:" and "References:" headers when replying to a message. This results in broken discussions because Mutt-ng has not enough information to guess the correct threading. You can fix this by tagging the reply, then moving to the parent message and using the ``link-threads'' function (bound to & by default). The reply will then be connected to this "parent" message.

You can also connect multiple children at once, tagging them and using the tag-prefix command (';') or the auto_tag option.

#### Breaking threads

On mailing lists, some people are in the bad habit of starting a new discussion by hitting "reply" to any message from the list and changing the subject to a totally unrelated one. You can fix such threads by using the ``break-thread'' function (boundby default to #), which will turn the subthread starting from the current message into a whole different thread.

### Delivery Status Notification (DSN) Support

defines a set of MIME content types for relaying information about the status of electronic mail messages. These can be thought of as ``return receipts.''

Users can make use of it in one of the following two ways:

- Berkeley sendmail 8.8.x currently has some command line options in which the mail client can make requests as to what type of status messages should be returned.

- The SMTP support via libESMTP supports it, too.

To support this, there are two variables:

- is used to request receipts for different results (such as failed message,message delivered, etc.).

- requests how much of your message should be returned with the receipt (headers or full message).

Please see the reference chapter for possible values.

### POP3 Support (OPTIONAL)

If Mutt-ng was compiled with POP3 support (by running the configure script with the --enable-pop flag), it has the ability to work with mailboxes located on a remote POP3 server and fetch mail for local browsing.

You can access the remote POP3 mailbox by selecting the folder `pop://popserver/`.

You can select an alternative port by specifying it with the server, i.e.: `pop://popserver:port/`.

You can also specify different username for each folder, i.e.: `pop://username@popserver[:port]/`.

Polling for new mail is more expensive over POP3 than locally. For this reason the frequency at which Mutt-ng will check for mail remotely can be controlled by the variable, which defaults to every 60 seconds.

If Mutt-ng was compiled with SSL support (by running the configure script with the --with-ssl flag), connections to POP3 servers can be encrypted. This naturally requires that the server supports SSL encrypted connections. To access a folder with POP3/SSL, you should use pops: prefix, ie: `pops://[username@]popserver[:port]/`.

Another way to access your POP3 mail is the fetch-mail function (default: G). It allows to connect to pop-host ,fetch all your new mail and place it in the local . After this point, Mutt-ng runs exactly as if the mail had always been local.

Note: If you only need to fetch all messages to local mailbox you should consider using a specialized program, such as .

### IMAP Support (OPTIONAL)

If Mutt-ng was compiled with IMAP support (by running the configure script with the --enable-imap flag), it has the ability to work with folders located on a remote IMAP server.

You can access the remote inbox by selecting the folder via its URL:

    imap://imapserver/INBOX

where `imapserver` is the name of the IMAP server and `INBOX` is the special name for your spool mailbox on the IMAP server. If you want to access another mail folder at the IMAP server, you should use

    imap://imapserver/path/to/folder

where `path/to/folder` is the path of the folder you want to access. You can select an alternative port by specifying it with the server, i.e.:

    imap://imapserver:port/INBOX

You can also specify different username for each folder by prenpending your username and an @ symbol to the server's name.

If Mutt-ng was compiled with SSL support (by running the configure script with the --with-ssl flag), connections to IMAP servers can be encrypted. This naturally requires that the server supports SSL encrypted connections. To access a folder with IMAP/SSL, you only need to substitute the initial `imap://` by `imaps://` in the above examples.

Note that not all servers use / as the hierarchy separator. Mutt-ng should correctly notice which separator is being used by the server and convertpaths accordingly.

When browsing folders on an IMAP server, you can toggle whether to look at only the folders you are subscribed to, or all folders with the toggle-subscribed command. See also the variable.

Polling for new mail on an IMAP server can cause noticeable delays. So, you'll want to carefully tune the and variables.

Note that if you are using mbox as the mail store on UW servers prior tov12.250, the server has been reported to disconnect a client if another client selects the same folder.

#### The Folder Browser

As of version 1.2, mutt supports browsing mailboxes on an IMAP server. This is mostly the same as the local file browser, with the following differences:

- Instead of file permissions, mutt displays the string "IMAP", possibly followed by the symbol "+", indicating that the entry contains both messages and subfolders. On Cyrus-like servers folders will often contain both messages and subfolders.

- For the case where an entry can contain both messages and subfolders, the selection key (bound to `enter` by default) will choose to descend into the subfolder view. If you wish to view the messages in that folder, you must use `view-file` instead (bound to `space` by default).

- You can create, delete and rename mailboxes with the `create-mailbox`, `delete-mailbox`, and `rename-mailbox` commands (default bindings: `C` , `d` and `r`, respectively). You may also `subscribe` and `unsubscribe` to mailboxes (normally these are bound to `s` and `u`, respectively).

#### Authentication

Mutt-ng supports four authentication methods with IMAP servers: SASL, GSSAPI, CRAM-MD5, and LOGIN (there is a patch by Grant Edwards to add NTLM authentication for you poor exchange users out there, but it has yet to be integrated into the main tree). There is also support for the pseudo-protocol ANONYMOUS, which allows you to log in to a public IMAP server without having an account. To use ANONYMOUS, simply make your username blank or "anonymous".

SASL is a special super-authenticator, which selects among several protocols (including GSSAPI, CRAM-MD5, ANONYMOUS, and DIGEST-MD5) the most secure method available on your host and the server. Using some of these methods (including DIGEST-MD5 and possibly GSSAPI), your entire session will be encrypted and invisible to those teeming network snoops. It is the best option if you have it. To use it, you must have the Cyrus SASL libraryinstalled on your system and compile mutt with the --with-sasl flag.

Mutt-ng will try whichever methods are compiled in and available on the server, in the following order: SASL, ANONYMOUS, GSSAPI, CRAM-MD5, LOGIN.

There are a few variables which control authentication:

- - controls the username under which you request authentication on the IMAP server, for all authenticators. This is overridden by an explicit username in the mailbox path (i.e. by using a mailbox name of the form `{user@host}`).

- - a password which you may preset, used by all authentication methods where a password is needed.

- - a colon-delimited list of IMAP authentication methods to try, in the order you wish to try them. If specified, this overrides mutt's default (attempt everything, in the order listed above).

### NNTP Support (OPTIONAL)

If compiled with ``--enable-nntp'' option, Mutt-ng can read news from a newsserver via NNTP. You can open a newsgroup with the ``change-newsgroup'' function from the index/pager which is by default bound to i.

The Default newsserver can be obtained from the environment variable. Like other news readers, info about subscribed newsgroups is saved in a file as specified by the variable. Article headers are cached and can be loaded from a file when a newsgroup is entered instead loading from newsserver; currently, this caching mechanism still is different from the header caching for maildir/IMAP.

#### Again: Scoring

Especially for Usenet, people often ask for advanced filtering and scoring functionality. Of course, mutt-ng has scoring and allows a killfile, too. How to use a killfile has been discussed in Message Scoring.

What has not been discusses in detail is mutt-ng's built-in realname filter. For may newsreaders including those for ``advanced users'' like slrn or tin, there are frequent request for such functionality. The solutions offered often are complicated regular expressions.

In mutt-ng this is as easy as

score ~* =42

This tells mutt-ng to apply a score of 42 to all messages whose sender specified a valid realname and a valid email address. Using

score !~* =42

on the contrary applies a score of 42 to all messages not matching those criteria which are very strict:

- Email addresses must be valid according to

- the name must consist of at least 2 fields whereby a field must not end in a dot. This means that ``Joe User'' and ``Joe A.User'' are valid while ``J. User'' and ``J. A. User'' aren't.

- it's assumed that users are interested in reading their own mail and mail from people who they have defined an alias forso that those 2 groups of messages are excluded from the strict rules.

### SMTP Support (OPTIONAL)

Mutt-ng can be built using a library called ``libESMTP'' which provides SMTP functionality. When `configure` was called with `--with-libesmtp` or the output `muttng -v` contains `+USE_LIBESMTP`, this will be or is the case already. The SMTP support includes support for Delivery Status Notification (see dsn section) as well as handling the `8BITMIME` flag controlled via .

To enable sending mail directly via SMTP without an MTA such as Postfix or SSMTP and the like, simply set the variable pointing to your SMTP server.

Authentication mechanisms are available via the and variables.

Transport Encryption via the StartTLS command is also available. For this to work, first of all Mutt-ng must be built with SSL or GNUTLS. Secondly, the variable must be either set to ``enabled'' or ``required.'' In both cases, StartTLS will be used if the server supports it: for the second case, the connection will fail ifit doesn't while switching back to unencrypted communication for the first one.

Some mail providers require user's to set a particular envelope sender, i.e. they allow for only one value which may not be what the user wants to send as the `From:` header. In this case, the variable may be used to set the envelope different from the `From:` header.

### Managing multiple IMAP/POP/NNTP accounts (OPTIONAL)

If you happen to have accounts on multiple IMAP and/or POP servers, you may find managing all the authentication settings inconvenient and error-prone. The command may help. This hook works like but is invoked whenever you access a remote mailbox (including inside the folder browser), not just when you open the mailbox.

Some examples:

account-hook . 'unset imap_user; unset imap_pass; unset tunnel' account-hook imap://host1/ 'set imap_user=me1 imap_pass=foo' account-hook imap://host2/ 'set tunnel="ssh host2 /usr/libexec/imapd"'

### Start a WWW Browser on URLs (EXTERNAL)

If a message contains URLs (unified resource locator = address in the WWW space like http://www.mutt.org/), it is efficient to get a menu with all the URLs and start a WWW browser on one of them. This functionality is provided by the external urlview program which can be retrieved at and the configuration commands:

macro index \cb |urlview\n macro pager \cb |urlview\n

### Compressed folders Support (OPTIONAL)

If Mutt-ng was compiled with compressed folders support (by running the configure script with the --enable-compressed flag), Mutt can open folders stored in an arbitrary format, provided that the user has a script to convert from/to this format to one of the accepted.

The most common use is to open compressed archived folders e.g. with gzip.

In addition, the user can provide a script that gets a folder in an accepted format and appends its context to the folder in the user-defined format, which may be faster than converting the entire folder to the accepted format, appending to it and converting back to the user-defined format.

There are three hooks defined (, and )which define commands to uncompress and compress a folder and to append messages to an existing compressed folder respectively.

For example:

open-hook \\.gz$ "gzip -cd %f > %t" close-hook \\.gz$ "gzip -c %t > %f" append-hook \\.gz$ "gzip -c %t >> %f"

You do not have to specify all of the commands. If you omit ,the folder will be open and closed again each time you will add to it. If you omit (or give empty command) , the folder will be open in the mode. If you specify though you'll be able to append to the folder.

Note that Mutt-ng will only try to use hooks if the file is not in one of the accepted formats. In particular, if the file is empty, mutt supposes it is not compressed. This is important because it allows the use of programs that do not have well defined extensions. Just use "." as a regexp. But this may be surprising if your compressing script produces empty files. In this situation, unset ,so that the compressed file will be removed if you delete all of the messages.

#### Open a compressed mailbox for reading

Usage: regexp "command"

The command is the command that can be used for opening the folders whose names match regexp.

The command string is the printf-like format string, and it should accept two parameters: %f, which is replaced with the (compressed) folder name, and %t which is replaced with the name of the temporary folder to which to write.

%f and %t can be repeated any number of times in the command string, and all of the entries are replaced with the appropriate folder name. In addition, %% is replaced by %, as in printf, and any other %anything is left as is.

The command should not remove the original compressed file. The command should return non-zero exit status if it fails, so mutt knows something's wrong.

Example:

open-hook \\.gz$ "gzip -cd %f > %t"

If the command is empty, this operation is disabled for this file type.

#### Write a compressed mailbox

Usage: regexp"command"

This is used to close the folder that was open with the command after some changes were made to it.

The command string is the command that can be used for closing the folders whose names match regexp. It has the same format as in the command. Temporary folder in this case is the folder previously produced by the command.

The command should not remove the decompressed file. The command should return non-zero exit status if it fails, so mutt knows something's wrong.

Example:

close-hook \\.gz$ "gzip -c %t > %f"

If the command is empty, this operation is disabled for this file type, and the file can only be open in the readonly mode.

is not called when you exit from the folder if the folder was not changed.

#### Append a message to a compressed mailbox

Usage: regexp"command"

This command is used for saving to an existing compressed folder. The command is the command that can be used for appending to the folders whose names match regexp. It has the same format as in the command. The temporary folder in this case contains the messages that are beingappended.

The command should not remove the decompressed file. The command should return non-zero exit status if it fails, so mutt knows something's wrong.

Example:

append-hook \\.gz$ "gzip -c %t >> %f"

When is used, the folder is not opened, which saves time, but this means that we can not find out what the folder type is. Thus the default ( )type is always supposed (i.e. this is the format used for the temporary folder).

If the file does not exist when you save to it, is called, and not . is only for appending to existing folders.

If the command is empty, this operation is disabled for this file type. In this case, the folder will be open and closed again (using and respectively) each time you will add to it.

#### Encrypted folders

The compressed folders support can also be used to handle encrypted folders. If you want to encrypt a folder with PGP, you may want to usethe following hooks:

open-hook \\.pgp$ "pgp -f < %f > %t" close-hook \\.pgp$ "pgp -fe YourPgpUserIdOrKeyId < %t > %f"

Please note, that PGP does not support appending to an encrypted folder, so there is no defined.

Note: the folder is temporary stored decrypted in the /tmp directory, where it can be read by your system administrator. So thinkabout the security aspects of this.

## Mutt-ng's MIME Support

Quite a bit of effort has been made to make Mutt-ng the premier text-mode MIME MUA. Every effort has been made to provide the functionality that the discerning MIME user requires, and the conformance to the standards wherever possible. When configuring Mutt-ng for MIME, there are two extratypes of configuration files which Mutt-ng uses. One is the `mime.types` file, which contains the mapping of file extensions to IANA MIME types. The other is the `mailcap` file, which specifies the external commands to use for handling specific MIME types.

### Using MIME in Mutt

There are three areas/menus in Mutt-ng which deal with MIME, they are the pager (while viewing a message), the attachment menu and the compose menu.

#### Viewing MIME messages in the pager

When you select a message from the index and view it in the pager, Mutt decodes the message to a text representation. Mutt-ng internally supports a number of MIME types, including `text/plain, text/enriched, message/rfc822, and message/news` .In addition, the export controlled version of Mutt-ng recognizes a variety of PGP MIME types, including PGP/MIME and application/pgp.

Mutt-ng will denote attachments with a couple lines describing them. These lines are of the form:

    [-- Attachment #1: Description --]
    [-- Type: text/plain, Encoding: 7bit, Size: 10000 --]

Where the `Description` is the description or filename given for the attachment, and the `Encoding` is one of `7bit/8bit/quoted-printable/base64/binary`.

If Mutt-ng cannot deal with a MIME type, it will display a message like:

    [-- image/gif is unsupported (use 'v' to view this part) --]

#### The Attachment Menu

The default binding for `view-attachments` is `v', which displays the attachment menu for a message. The attachment menu displays a list ofthe attachments in a message. From the attachment menu, you can save, print, pipe, delete, and view attachments. You can apply these operations to a group of attachments at once, by tagging the attachments and by using the ``tag-prefix'' operator. You can also reply to the current message from this menu, and only the current attachment (or the attachments tagged) will be quoted in your reply. You can view attachments as text, or view them using the mailcap viewer definition.

Finally, you can apply the usual message-related functions (like , and the reply and forward functions) to attachments of type `message/rfc822`.

See the help on the attachment menu for more information.

#### The Compose Menu

The compose menu is the menu you see before you send a message. It allows you to edit the recipient list, the subject, and other aspects of your message. It also contains a list of the attachments of your message, including the main body. From this menu, you can print, copy, filter, pipe, edit, compose, review, and rename an attachment or a list of tagged attachments. You can also modifying the attachment information, notably the type, encoding and description.

Attachments appear as follows:

    1 [text/plain, 7bit, 1K]             /tmp/mutt-euler-8082-0 <no description>
    2 [applica/x-gunzip, base64, 422K]   ~/src/mutt-0.85.tar.gz <no description>

The '-' denotes that Mutt-ng will delete the file after sending (or postponing, or canceling) the message. It can be toggled with the `toggle-unlink` command (default: u). The next field is the MIME content-type, and can be changed with the `edit-type` command (default: ^T). The next field is the encoding for the attachment, which allows a binary message to be encoded for transmission on 7bit links. It can be changed with the `edit-encoding` command (default: ^E). The next field is the size of the attachment, rounded to kilobytes or megabytes. The next field is the filename, which can be changed with the `rename-file` command (default: R). The final field is the description of the attachment, and can be changed with the `edit-description` command (default: d).

### MIME Type configuration with `mime.types`

When you add an attachment to your mail message, Mutt-ng searches your personal mime.types file within and then the system mime.types file at `/usr/local/share/mutt/mime.types` or `/etc/mime.types`

The mime.types file consist of lines containing a MIME type and a space separated list of extensions. For example:

    application/postscript          ps eps
    application/pgp                 pgp
    audio/x-aiff                    aif aifc aiff

A sample `mime.types` file comes with the Mutt-ng distribution, and should contain most of the MIME types you are likely to use.

If Mutt-ng can not determine the mime type by the extension of the file you attach, it will look at the file. If the file is free of binary information, Mutt-ng will assume that the file is plain text, and mark it as `text/plain`. If the file contains binary information, then Mutt-ng will mark it as `application/octet-stream`. You can change the MIME type that Mutt-ng assigns to an attachment by using the `edit-type` command from the compose menu (default: ^T). The MIME type is actually a major mime type followed by the sub-type, separated by a '/'. 6 major types: application, text, image, video, audio, and model have been approved after various internet discussions. Mutt-ng recognises all of these if the appropriate entry is found in the mime.types file. It also recognises other major mime types, such as the chemical type that is widely used in the molecular modelling community to pass molecular data in various forms to various molecular viewers. Non-recognised mime types should only be used if the recipient of the message is likely to be expecting such attachments.

### MIME Viewer configuration with `mailcap`

Mutt-ng supports MIME Configuration, in particular the Unix specific format specified in Appendix A of the RfC. This file format is commonly referred to as the mailcap format. Many MIME compliant programs utilize the mailcap format, allowing you to specify handling for all MIME types in one place for all programs. Programs known to use this format include Netscape, XMosaic, lynx and metamail.

In order to handle various MIME types that Mutt-ng can not handle internally, Mutt-ng parses a series of external configuration files to find an external handler. The default search string for these files is a colon delimited list set to

    ${HOME}/.mailcap:/usr/local/share/mutt/mailcap:/etc/mailcap:/etc/mailcap:/usr/etc/mailcap:/usr/local/etc/mailcap

where is your home directory.

In particular, the metamail distribution will install a mailcap file, usually as `/usr/local/etc/mailcap`, which contains some baseline entries.

#### The Basics of the mailcap file

A mailcap file consists of a series of lines which are comments, blank, or definitions.

A comment line consists of a # character followed by anything you want.

A blank line is blank.

A definition line consists of a content type, a view command, and any number of optional fields. Each field of a definition line is dividedby a semicolon ';' character.

The content type is specified in the MIME standard type/subtype method. For example, `text/plain, text/html, image/gif,` etc. In addition, the mailcap format includes two formats for wildcards, one using the special '*' subtype, the other is the implicit wild, where you only include the major type. For example, `image/*` ,or `video,` will match all image types and video types, respectively.

The view command is a Unix command for viewing the type specified. There are two different types of commands supported. The default is to send the body of the MIME message to the command on stdin. You can change this behavior by using %s as a parameter to your view command. This will cause Mutt-ng to save the body of the MIME message to a temporary file, and then call the view command with the %s replaced by the name of the temporary file. In both cases, Mutt-ng will turn over the terminal to the view program until the program quits, at which time Mutt will remove the temporary file if it exists.

So, in the simplest form, you can send a text/plain message to the external pager more on stdin:

    text/plain; more

Or, you could send the message as a file:

    text/plain; more %s

Perhaps you would like to use lynx to interactively view a text/html message:

    text/html; lynx %s

In this case, lynx does not support viewing a file from stdin, so you must use the %s syntax. Note: Some older versions of lynx contain a bug where they will check the mailcap file for a viewer for text/html. They will find the line which calls lynx, and run it. This causes lynx to continuously spawn itself to view the object.

On the other hand, maybe you don't want to use lynx interactively, youjust want to have it convert the text/html to text/plain, then you can use:

    text/html; lynx -dump %s | more

Perhaps you wish to use lynx to view text/html files, and a pager on all other text formats, then you would use the following:

    text/html; lynx %s
    text/*; more

This is the simplest form of a mailcap file.

#### Secure use of mailcap

The interpretation of shell meta-characters embedded in MIME parameters can lead to security problems in general. Mutt-ng tries to quote parameters in expansion of %s syntaxes properly, and avoids risky characters by substituting them, see the variable.

Although mutt's procedures to invoke programs with mailcap seem to be safe, there are other applications parsing mailcap, maybe taking less care of it. Therefore you should pay attention to the following rules:

Keep the %-expandos away from shell quoting. Don't quote them with single or double quotes. Mutt-ng does this for you, the right way, as should any other program which interprets mailcap. Don't put them into backtick expansions. Be highly careful with eval statements, and avoid them if possible at all. Trying to fix broken behaviour with quotes introduces new leaks - there is no alternative to correct quoting in the first place.

If you have to use the %-expandos' values in context where you need quoting or backtick expansions, put that value into a shell variable and reference the shell variable where necessary, as in the following example (using `$charset` inside the backtick expansion is safe, since it is not itself subject to any further expansion):

    text/test-mailcap-bug; cat %s; copiousoutput; test=charset=%{charset} \
    && test "`echo $charset | tr '[A-Z]' '[a-z]'`" != iso-8859-1

#### Advanced mailcap Usage

##### Optional Fields

In addition to the required content-type and view command fields, you can add semi-colon ';' separated fields to set flags and other options. Mutt-ng recognizes the following optional fields:

copiousoutput

  This flag tells Mutt-ng that the command passes possibly large amounts of text on stdout. This causes Mutt-ng to invoke a pager (either the internal pager or the external pager defined by the pager variable) on the output of the view command. Without this flag, Mutt-ng assumes that the command is interactive. One could use this to replace the pipe to `more` in the `lynx -dump` example in the Basic section:

      text/html; lynx -dump %s ; copiousoutput

  This will cause lynx to format the text/html output as text/plain and Mutt-ng will use your standard pager to display the results.
needsterminal

  Mutt-ng uses this flag when viewing attachments with , in order to decide whether it should honor the setting of the variable or not. When an attachment is viewed using an interactive program, and the corresponding mailcap entry has a needsterminal flag, Mutt-ng will use and the exit statusof the program to decide if it will ask you to press a key after the external program has exited. In all other situations it will not prompt you for a key.

compose=<command>

  This flag specifies the command to use to create a new attachment of a specific MIME type. Mutt-ng supports this from the compose menu.

composetyped=<command>

  This flag specifies the command to use to create a new attachment of a specific MIME type. This command differs from the compose command in that mutt will expect standard MIME headers on the data. This can be used to specify parameters, filename, description, etc. for a new attachment. Mutt-ng supports this from the compose menu.

print=<command>

  This flag specifies the command to use to print a specific MIME type. Mutt-ng supports this from the attachment and compose menus.

edit=<command>

  This flag specifies the command to use to edit a specific MIME type. Mutt-ng supports this from the compose menu, and also uses it to compose new attachments. Mutt-ng will default to the defined editor for text attachments.

nametemplate=<template>

  This field specifies the format for the file denoted by %s in the command fields. Certain programs will require a certain file extension, for instance, to correctly view a file. For instance, lynx will only interpret a file as `text/html` if the file ends in `.html`. So, you would specify lynx as a `text/html` viewer with a line in the mailcap file like:

      text/html; lynx %s; nametemplate=%s.html

test=<command>

  This field specifies a command to run to test whether this mailcap entry should be used. The command is defined with the command expansion rules defined in the next section. If the command returns 0, then the test passed, and Mutt-ng uses this entry. If the command returns non-zero, then the test failed, and Mutt-ng continues searching for the right entry. Note: the content-type must match before Mutt-ng performs the test. For example:

      text/html; netscape -remote 'openURL(%s)' ; test=RunningX
      text/html; lynx %s

  In this example, Mutt-ng will run the program RunningX which will return 0 if the X Window manager is running, and non-zero if it isn't. If RunningX returns 0, then Mutt-ng will call netscape to display the text/html object. If RunningX doesn't return 0, then Mutt-ng will go on to the next entry and use lynx to display the text/html object.

##### Search Order

When searching for an entry in the mailcap file, Mutt-ng will search for the most useful entry for its purpose. For instance, if you are attempting to print an `image/gif`, and you have the following entries in your mailcap file, Mutt-ng will search for an entry with the print command:

    image/*;        xv %s
    image/gif;      ; print= anytopnm %s | pnmtops | lpr; \
    nametemplate=%s.gif

Mutt-ng will skip the `image/*` entry and use the `image/gif` entry with the print command.

In addition, you can use this with to denote two commands for viewing an attachment, one to be viewed automatically, the other to be viewed interactively from the attachment menu. In addition, you can then use the test feature to determine which viewer to use interactively depending on your environment.

    text/html;      netscape -remote 'openURL(%s)' ; test=RunningX
    text/html;      lynx %s; nametemplate=%s.html
    text/html;      lynx -dump %s; nametemplate=%s.html; copiousoutput

For , Mutt-ng will choose the third entry because of the copiousoutput tag. For interactive viewing, Mutt will run the program RunningX to determine if it should use the first entry. If the program returns non-zero, Mutt-ng will use the second entry for interactive viewing.

##### Command Expansion

The various commands defined in the mailcap files are passed to the `/bin/sh` shell using the system() function. Before the command is passed to `/bin/sh -c`, it is parsed to expand various special parameters with information from Mutt-ng. The keywords Mutt-ng expands are:

%s

  As seen in the basic mailcap section, this variable is expanded to a filename specified by the calling program. This file contains the body of the message to view/print/edit or where the composing program should place the results of composition. In addition, the use of this keyword causes Mutt-ng to not pass the body of the message to the view/print/edit program on stdin.

%t

  Mutt-ng will expand %t to the text representation of the content type of the message in the same form as the first parameter of the mailcap definition line, ie `text/html` or `image/gif`.

%{<parameter>}

  Mutt-ng will expand this to the value of the specified parameter from the Content-Type: line of the mail message. For instance, if Your mail message contains:

  Content-Type: text/plain; charset=iso-8859-1

  then Mutt-ng will expand %{charset} to iso-8859-1. The default metamail mailcap file uses this feature to test the charset to spawn an xterm using the right charset to view the message.

\%

  This will be replaced by a %

Mutt-ng does not currently support the %F and %n keywords specified in . The main purpose of these parameters is for multipart messages, which is handled internally by Mutt-ng.

#### Example mailcap files

This mailcap file is fairly simple and standard:

    >
    # I'm always running X :)
    video/*;        xanim %s > /dev/null
    image/*;        xv %s > /dev/null

    # I'm always running netscape (if my computer had more memory, maybe)
    text/html;      netscape -remote 'openURL(%s)'

This mailcap file shows quite a number of examples:

    # Use xanim to view all videos   Xanim produces a header on startup,
    # send that to /dev/null so I don't see it
    video/*;        xanim %s > /dev/null

    # Send html to a running netscape by remote
    text/html;      netscape -remote 'openURL(%s)'; test=RunningNetscape
    # If I'm not running netscape but I am running X, start netscape on the
    # object
    text/html;      netscape %s; test=RunningX

    # Else use lynx to view it as text
    text/html;      lynx %s

    # This version would convert the text/html to text/plain
    text/html;      lynx -dump %s; copiousoutput

    # I use enscript to print text in two columns to a page
    text/*;         more %s; print=enscript -2Gr %s

    # Netscape adds a flag to tell itself to view jpegs internally
    image/jpeg;xv %s; x-mozilla-flags=internal

    # Use xv to view images if I'm running X
    # In addition, this uses the \ to extend the line and set my editor
    # for images
    image/*;xv %s; test=RunningX; edit=xpaint %s

    # Convert images to text using the netpbm tools
    image/*;  (anytopnm %s | pnmscale -xysize 80 46 | ppmtopgm | \
    pgmtopbm | pbmtoascii -1x2 ) 2>&1 ; copiousoutput

    # Send excel spreadsheets to my NT box
    application/ms-excel; open.pl %s

### MIME Autoview

mime-type [mime-type ...]

mime-type [mime-type ...]

In addition to explicitly telling Mutt-ng to view an attachment with theMIME viewer defined in the mailcap file, Mutt-ng has support for automatically viewing MIME attachments while in the pager.

To work, you must define a viewer in the mailcap file which uses the `copiousoutput` option to denote that it is non-interactive. Usually, you also use the entry to convert the attachment to a text representation which you can view in the pager.

You then use the `auto_view` muttrc command to list the content-types that you wish to view automatically.

For instance, if you set auto_view to:

auto_view text/html application/x-gunzip application/postscript image/gif application/x-tar-gz

Mutt-ng could use the following mailcap entries to automatically view attachments of these types.

    text/html;      lynx -dump %s; copiousoutput; nametemplate=%s.html
    image/*;        anytopnm %s | pnmscale -xsize 80 -ysize 50 | ppmtopgm | pgmtopbm | pbmtoascii ; copiousoutput
    application/x-gunzip;   gzcat; copiousoutput
    application/x-tar-gz; gunzip -c %s | tar -tf - ; copiousoutput
    application/postscript; ps2ascii %s; copiousoutput

``unauto_view'' can be used to remove previous entries from the autoview list. This can be used with to autoview messages based on size, etc. ``unauto_view *'' will remove all previous entries.

### MIME Multipart/Alternative

mime-type [mime-type ...]

mime-type [mime-type ...]

Mutt-ng has some heuristics for determining which attachment of a multipart/alternative type to display. First, mutt will check the alternative_order list to determine if one of the available typesis preferred. The alternative_order list consists of a number of MIME types in order, including support for implicit and explicit wildcards, for example:

alternative_order text/enriched text/plain text application/postscript image/*

Next, mutt will check if any of the types have a defined , and use that. Failing that, Mutt-ng will look for any text type. As a last attempt, mutt willlook for any type it knows how to handle.

To remove a MIME type from the `alternative_order` list, use the `unalternative_order` command.

### Attachment Searching and Counting

If you ever lose track of attachments in your mailboxes, Mutt's attachment-counting and -searching support might be for you. You can make your message index display the number of qualifying attachments in each message, or search for messages by attachment count. You also can configure what kinds of attachments qualify for this feature with the attachments and unattachments commands.

The syntax is:

( {+|-}disposition mime-type | ? )

{+|-}disposition mime-type

Disposition is the attachment's Content-disposition type -- either "inline" or "attachment". You can abbreviate this to I or A.

Disposition is prefixed by either a + symbolor a - symbol. If it's a +, you're saying that you want to allow this disposition and MIME type to qualify. If it's a -, you're saying that this disposition and MIME type is an exception to previous + rules. There are examples below of how this is useful.

Mime-type is, unsurprisingly, the MIME type of the attachment you want to affect. A MIME type is always of the format "major/minor", where "major" describes the broad category of document you're looking at, and "minor" describes the specific type within that category. The major part of mim-type must be literal text (or the special token "*"), but the minor part may be a regular expression. (Therefore, "*/.*" matches any MIME type.)

The MIME types you give to the attachments directive are a kind of pattern. When you use the attachments directive, the patterns you specify are added to a list. When you use unattachments, the pattern is removed from the list. The patterns are not expanded and matched to specific MIME types at this time -- they're just text in a list. They're only matched when actually evaluating a message.

Some examples might help to illustrate. The examples that are not commented out define the default configuration of the lists.

    ## Removing a pattern from a list removes that pattern literally. It
    ## does not remove any type matching the pattern.
    ##
    ## attachments +A */.*
    ## attachments +A image/jpeg
    ## unattachments +A */.*
    ##
    ## This leaves "attached" image/jpeg files on the allowed attachments
    ## list. It does not remove all items, as you might expect, because the
    ## second */.* is not a matching expression at this time.
    ##
    ## Remember: "unattachments" only undoes what "attachments" has done!
    ## It does not trigger any matching on actual messages.

    ## Qualify any MIME part with an "attachment" disposition, EXCEPT for
    ## text/x-vcard and application/pgp parts. (PGP parts are already known
    ## to mutt, and can be searched for with ~g, ~G, and ~k.)
    ##
    ## I've added x-pkcs7 to this, since it functions (for S/MIME)
    ## analogously to PGP signature attachments. S/MIME isn't supported
    ## in a stock mutt build, but we can still treat it specially here.
    ##
    attachments +A */.*
    attachments -A text/x-vcard application/pgp.*
    attachments -A application/x-pkcs7-.*

    ## Discount all MIME parts with an "inline" disposition, unless they're
    ## text/plain. (Why inline a text/plain part unless it's external to the
    ## message flow?)
    ##
    attachments +I text/plain

    ## These two lines make Mutt qualify MIME containers. (So, for example,
    ## a message/rfc822 forward will count as an attachment.) The first
    ## line is unnecessary if you already have "attach-allow */.*", of
    ## course. These are off by default! The MIME elements contained
    ## within a message/* or multipart/* are still examined, even if the
    ## containers themseves don't qualify.
    ##
    #attachments +A message/.* multipart/.*
    #attachments +I message/.* multipart/.*

    ## You probably don't really care to know about deleted attachments.
    attachments -A message/external-body
    attachments -I message/external-body

"attachments ?" will list your current settings in Muttrc format, so that it can be pasted elsewhere.

Please note that counting attachments may require lots of data be loaded. This may cause noticeable slowdowns over network links depending on the connection speed and message sizes. To fine-tune the behavior on a per-folder or other basis, the variable may be used.

### MIME Lookup

mime-type [mime-type ...]

mime-type [mime-type ...]

Mutt-ng's mime_lookup list specifies a list of mime-types that should not be treated according to their mailcap entry. This option is designed todeal with binary types such as application/octet-stream. When an attachment's mime-type is listed in mime_lookup, then the extension of the filename will be compared to the list of extensions in the mime.types file. The mime-type associated with this extension will then be used to process the attachment according to the rules in the mailcap file and according to any other configuration options (such as auto_view) specified. Common usage would be:

mime_lookup application/octet-stream application/X-Lotus-Manuscript

In addition, the unmime_lookup command may be used to disable this feature for any particular mime-type if it had been set, for example, in a global muttrc.

## Security Considerations

First of all, mutt-ng contains no security holes included by intention but may contain unknown security holes. As a consequence, please run mutt-ng only with as few permissions as possible.

Please do not run mutt-ng as the super user.

When configuring mutt-ng, there're some points to note about secure setups.

In practice, mutt-ng can be easily made as vulnerable as even the most insecure mail user agents (in their default configuration) just by changing mutt-ng's configuration files: it then can execute arbitrary programs and scripts attached to messages, send out private data on its own, etc. Although this is not believed to the common type of setup, please read this chapter carefully.

### Passwords

Although mutt-ng can be told the various passwords for accounts, please never store passwords in configuration files. Besides the fact that the system's operator can always read them, you could forget to replace the actual password with asterisks when reporting a bug or asking for help via, for example, a mailing list so that your mail including your password could be archived by internet search engines, etc. Please never store passwords on disk.

### Temporary Files

Mutt-ng uses many temporary files for viewing messages, verifying digital signatures, etc. The variable can be used to change the default permissions of these files. Please only change it if you really know what you are doing. Also, a different location for these files may be desired which can be changed via the variable.

### Information Leaks

#### Message-ID: headers

In the default configuration, mutt-ng will leak some information to the outside world when sending messages: the generation of `Message-ID:` headers includes a step counter which is increased (and rotated) with every message sent. If you'd like to hide this information probably telling others how many mail you sent in which time, you at least need to remove the `%P` expando from the default setting of the variable. Please make sure that you really know how local parts of these `Message-ID:` headers are composed.

#### mailto:-style links

As mutt-ng be can be set up to be the mail client to handle `mailto:` style links in websites, there're security considerations, too. To keep the old behavior by default, mutt-ng will be strict in interpreting them which means that arbitrary header fields can be embedded in these links which could override existing header fields or attach arbitrary files. This may be problematic if the variable is unset, i.e. the user doesn't want to see header fields while editing the message.

For example, following a link like

    mailto:joe@host?Attach=~/.gnupg/secring.gpg

will send out the user's private gnupg keyring to `joe@host` if the user doesn't follow the information on screen carefully enough.

When unsetting the variable, mutt-ng will

- be less strict when interpreting these links by prepending a `X-Mailto-` string to all header fields embedded in such a link and

- turn on the variable by force to let the user see all the headers (because they still may leak information.)

### External applications

Mutt-ng in many places has to rely on external applications or for convenience supports mechanisms involving external applications.

#### mailcap

One of these is the `mailcap` mechanism as defined by . Mutt-ng can be set up to automatically execute any given utility as listed in one of the mailcap files (see the variable for details.)

These utilities may have a variety of security vulnerabilities, including overwriting of arbitrary files, information leaks or other exploitable bugs. These vulnerabilities may go unnoticed by the user, especially when they are called automatically (and without interactive prompting) from the mailcap file(s). When using mutt-ng's autoview mechanism in combination with mailcap files, please be sure to...

- manually select trustworth applications with a reasonable calling sequence

- periodically check the contents of mailcap files, especially after software installations or upgrades

- keep the software packages referenced in the mailcap file up to date

- leave the variable in its default state to restrict mailcap expandos to a safe set of characters

#### Other

Besides the mailcap mechanism, mutt-ng uses a number of other external utilities for operation.

The same security considerations apply for these as for tools involved via mailcap (for example, mutt-ng is vulnerable to Denial of Service Attacks with compressed folders support if the uncompressed mailbox is too large for the disk it is saved to.)

As already noted, most of these problems are not built in but caused by wrong configuration, so please check your configuration.

## Reference

### Command line options

Running `mutt` with no arguments will make Mutt-ng attempt to read your spool mailbox. However, it is possible to read other mailboxes and to send messages from the command line as well.

#### Reference: Command Line Options

Option | Description
--- | ---
`-A` | expand an alias
`-a` | attach a file to a message
`-b` | specify a blind carbon-copy (BCC) address
`-c` | specify a carbon-copy (Cc) address
`-e` | specify a config command to be run after initialization files are read
`-f` | specify a mailbox to load
`-F` | specify an alternate file to read initialization commands
`-h` | print help on command line options
`-H` | specify a draft file from which to read a header and body
`-i` | specify a file to include in a message composition
`-m` | specify a default mailbox type
`-n` | do not read the system Muttngrc
`-p` | recall a postponed message
`-Q` | query a configuration variable
`-R` | open mailbox in read-only mode
`-s` | specify a subject (enclose in quotes if it contains spaces)
`-t` | dump the value of all variables to stdout
`-T` | dump the value of all changed variables to stdout
`-v` | show version number and compile-time definitions
`-x` | simulate the mailx(1) compose mode
`-y` | show a menu containing the files specified by the mailboxes command
`-z` | exit immediately if there are no messages in the mailbox
`-Z` | open the first folder with new message,exit immediately if none

To read messages in a mailbox

`mutt` ] -nz ] ] -F muttrc ] ] -m type ] ] -f mailbox ]

To compose a new message

`mutt` ] -n ] ] -F muttrc ] ] -a file ] ] -c address ] ] -i filename ] ] -s subject ] address ] address ... ]

Mutt-ng also supports a ``batch'' mode to send prepared messages. Simply redirect input from the file you wish to send. For example,

`mutt -s "data set for run #2" professor@bigschool.edu < ~/run2.dat`

This command will send a message to ``professor@bigschool.edu'' with a subject of ``data set for run #2''. In the body of the message will be the contents of the file ``~/run2.dat''.

### Patterns

#### Reference: Patterns

Pattern Modifier | Argument | Description
--- | --- | ---
| `` | all messages
| `EXPR` | messages which contain EXPR in the message body
| `EXPR` | messages which contain EXPR in the whole message
| `EXPR` | messages carbon-copied to EXPR
| `EXPR` | message is either to: or cc: EXPR
| `` | deleted messages
| `[MIN]-[MAX]` | messages with ``date-sent'' in a Date range
| `` | expired messages
| `EXPR` | message which contains EXPR in the ``Sender'' field
| `` | flagged messages
| `EXPR` | messages originating from EXPR
| `` | cryptographically signed messages
| `` | cryptographically encrypted messages
| `EXPR` | messages with a spam attribute matching EXPR
| `EXPR` | messages which contain EXPR in the message header
| `` | message contains PGP key material
| `EXPR` | message which match ID in the ``Message-ID'' field
| `EXPR` | message is either originated or received by EXPR
| `` | message is addressed to a known mailing list
| `[MIN]-[MAX]` | message in the range MIN to MAX *)
| `` | multipart messages
| `[MIN]-[MAX]` | messages with a score in the range MIN to MAX *)
| `` | new messages
| `` | old messages
| `` | message is addressed to you (consults alternates)
| `` | message is from you (consults alternates)
| `` | messages which have been replied to
| `` | read messages
| `[MIN]-[MAX]` | messages with ``date-received'' in a Date range
| `` | superseded messages
| `EXPR` | messages having EXPR in the ``Subject'' field.
| `` | tagged messages
| `EXPR` | messages addressed to EXPR
| `` | unread messages
| `` | message is addressed to a subscribed mailing list
| `` | message is part of a collapsed thread.
| `` | cryptographically verified messages
| `EXPR` | messages which contain EXPR in the `Newsgroups' field (if compiled with NNTP support)
| `EXPR` | messages which contain EXPR in the `References' field
| `[MIN]-[MAX]` | messages with MIN to MAX attachments *)
| `EXPR` | messages which contain EXPR in the `X-Label' field
| `[MIN]-[MAX]` | messages with a size in the range MIN to MAX *)
| `` | duplicated messages (see $duplicate_threads)
| `` | unreferenced messages (requires threaded view)
| `` | ``From'' contains realname and (syntactically) valid address (excluded are addresses matching against alternates or any alias)

Where EXPR are regexp. Special attention has to be made when using regular expressions inside of patterns. Specifically, Mutt-ng's parser for these patterns will strip one level of backslash (\), which is normally used for quoting. If it is your intention to use a backslash in the regular expression, you will need to use two backslashes instead (\\).

*) The forms `<[MAX]`, `>[MIN]`, `[MIN]-` and `-[MAX]` are allowed, too.

### Configuration Commands

The following are the commands understood by mutt.

- `` pattern command

- `` key address [, address, ... ]

- `` [ * | key ... ]

- `` regexp [ regexp ... ]

- `` [ * | regexp ... ]

- `` mimetype [ mimetype ... ]

- `` mimetype [ mimetype ... ]

- `` regexp command

- `` mimetype [ mimetype ... ]

- ``mimetype [ mimetype ... ]

- `` map key function

- `` alias charset

- `` regexp command

- `` object foreground background [ regexp ]

- `` index pattern [ pattern ... ]

- `` function [ function ... ]

- `` pattern mailbox

- `` pattern mailbox

- `` pattern command

- `` header [ header ... ]

- `` header [ header ... ]

- `` charset local-charset

- `` pattern [ pattern ... ]

- `` pattern [ pattern ... ]

- `` regexp [ regexp ... ]

- `` regexp [ regexp ... ]

- `` menu key sequence [ description ]

- `` filename [ filename ... ]

- `` pattern mailbox

- `` pattern command

- `` mimetype [ mimetype ... ]

- `` mimetype [ mimetype ... ]

- `` object attribute [ regexp ]

- `` index pattern [ pattern ... ]

- `` string

- `` field [ field ... ]

- `` regexp command

- `` pattern key-id

- `` string

- `` variable [ variable ... ]

- `` regexp filename

- `` pattern value

- `` pattern [ pattern ... ]

- `` regexp command

- `` regexp command

- `` [no|inv]variable[ =value ] [ variable ... ]

- `` variable [ variable ... ]

- `` filename

- `` pattern format

- `` pattern

- `` regexp [ regexp ... ]

- `` regexp [ regexp ... ]

- `` variable [ variable ... ]

- `` hook-type

### Configuration variables

The following list contains all variables which, in the process of providing more consistency, have been renamed and are partially even removed already. The left column contains the old synonym variables, the right column the full/new name:

#### Reference: Obsolete Variables

Old Name | New Name
--- | ---
`edit_hdrs` |
`forw_decode` |
`forw_format` |
`forw_quote` |
`hdr_format` |
`indent_str` |
`mime_fwd` |
`msg_format` |
`pgp_autosign` |
`pgp_autoencrypt` |
`pgp_replyencrypt` |
`pgp_replysign` |
`pgp_replysignencrypted` |
`pgp_verify_sig` |
`pgp_create_traditional` |
`pgp_auto_traditional` |
`forw_decrypt` |
`smime_sign_as` |
`post_indent_str` |
`print_cmd` |
`shorten_hierarchy` |
`ask_followup_to` |
`ask_x_comment_to` |
`catchup_newsgroup` |
`followup_to_poster` |
`group_index_format` |
`inews` |
`mime_subject` |
`news_cache_dir` |
`news_server` |
`newsrc` |
`nntp_poll` |
`pop_checkinterval` |
`post_moderated` |
`save_unsubscribed` |
`show_new_news` |
`show_only_unread` |
`x_comment_to` |
`smtp_auth_username` |
`smtp_auth_password` |
`user_agent` |

The `contrib` subdirectory contains a script named `update-config.pl` which eases migration.

A complete list of current variables follows.