    LMTP(8)                                                   LMTP(8)

    NAME
           lmtp - Postfix local delivery via LMTP

    SYNOPSIS
           lmtp [generic Postfix daemon options]

    DESCRIPTION
           The  LMTP  client processes message delivery requests from
           the queue manager. Each request specifies a queue file,  a
           sender address, a domain or host to deliver to, and recip-
           ient information.  This program expects to be run from the
           master(8) process manager.

           The  LMTP  client updates the queue file and marks recipi-
           ents as finished, or it informs  the  queue  manager  that
           delivery  should  be tried again at a later time. Delivery
           problem reports are sent to the bounce(8) or defer(8) dae-
           mon as appropriate.

           The  LMTP  client connects to the destination specified in
           the message delivery  request.  The  destination,  usually
           specified in the Postfix transport(5) table, has the form:

           unix:pathname
                  Connect to the local  UNIX-domain  server  that  is
                  bound  to  the  specified  pathname. If the process
                  runs chrooted, an absolute pathname is  interpreted
                  relative to the changed root directory.

           inet:host, inet:host:port (symbolic host)

           inet:[addr], inet:[addr]:port (numeric host)
                  Connect to the specified IPV4 TCP port on the spec-
                  ified local or remote host. If no  port  is  speci-
                  fied,  connect  to the port defined as lmtp in ser-
                  vices(4).   If  no  such  service  is  found,   the
                  lmtp_tcp_port   configuration   parameter  (default
                  value of 24) will be used.

                  The  LMTP  client  does  not   perform   MX   (mail
                  exchanger) lookups since those are defined only for
                  mail delivery via SMTP.

           If  neither  unix:  nor  inet:  are  specified,  inet:  is
           assumed.

    SECURITY
           The LMTP client is moderately security-sensitive. It talks
           to LMTP servers and to DNS servers  on  the  network.  The
           LMTP client can be run chrooted at fixed low privilege.

    STANDARDS
           RFC 821 (SMTP protocol)
           RFC 1651 (SMTP service extensions)
           RFC 1652 (8bit-MIME transport)
           RFC 1870 (Message Size Declaration)
           RFC 2033 (LMTP protocol)
           RFC 2554 (AUTH command)
           RFC 2821 (SMTP protocol)
           RFC 2920 (SMTP Pipelining)

    DIAGNOSTICS
           Problems  and transactions are logged to syslogd(8).  Cor-
           rupted message files are marked so that the queue  manager
           can move them to the corrupt queue for further inspection.

           Depending on the setting of the notify_classes  parameter,
           the  postmaster is notified of bounces, protocol problems,
           and of other trouble.

    BUGS
    CONFIGURATION PARAMETERS
           The following main.cf parameters are  especially  relevant
           to  this  program. See the Postfix main.cf file for syntax
           details and for default values.  Use  the  postfix  reload
           command after a configuration change.

    Miscellaneous
           debug_peer_level
                  Verbose  logging  level  increment  for  hosts that
                  match a pattern in the debug_peer_list parameter.

           debug_peer_list
                  List of domain or network patterns. When  a  remote
                  host  matches  a pattern, increase the verbose log-
                  ging  level  by  the  amount   specified   in   the
                  debug_peer_level parameter.

           error_notice_recipient
                  Recipient    of   protocol/policy/resource/software
                  error notices.

           notify_classes
                  When this parameter includes  the  protocol  class,
                  send  mail  to  the  postmaster with transcripts of
                  LMTP sessions with protocol errors.

           lmtp_skip_quit_response
                  Do not wait for the server response  after  sending
                  QUIT.

           lmtp_tcp_port
                  The  TCP  port to be used when connecting to a LMTP
                  server.  Used as backup if the lmtp service is  not
                  found in services(4).

    Authentication controls
           lmtp_sasl_auth_enable
                  Enable  per-session  authentication as per RFC 2554
                  (SASL).  By default, Postfix is built without  SASL
                  support.

           lmtp_sasl_password_maps
                  Lookup tables with per-host or domain name:password
                  entries.  No entry for a host means no  attempt  to
                  authenticate.

           lmtp_sasl_security_options
                  Zero or more of the following.

                  noplaintext
                         Disallow  authentication  methods  that  use
                         plaintext passwords.

                  noactive
                         Disallow  authentication  methods  that  are
                         vulnerable to non-dictionary active attacks.

                  nodictionary
                         Disallow  authentication  methods  that  are
                         vulnerable to passive dictionary attack.

                  noanonymous
                         Disallow anonymous logins.

    Resource controls
           lmtp_cache_connection
                  Should  we cache the connection to the LMTP server?
                  The effectiveness of  cached  connections  will  be
                  determined  by  the  number of LMTP servers in use,
                  and the concurrency limit specified  for  the  LMTP
                  client.  Cached connections are closed under any of
                  the following conditions:

                  o      The LMTP client idle time limit is  reached.
                         This  limit  is  specified  with the Postfix
                         max_idle configuration parameter.

                  o      A delivery  request  specifies  a  different
                         destination than the one currently cached.

                  o      The  per-process  limit  on  the  number  of
                         delivery requests is reached.  This limit is
                         specified  with the Postfix max_use configu-
                         ration parameter.

                  o      Upon the onset of another delivery  request,
                         the  LMTP server associated with the current
                         session does not respond to  the  RSET  com-
                         mand.

           transport_destination_concurrency_limit
                  Limit the number of parallel deliveries to the same
                  destination  via  this  mail  delivery   transport.
                  transport  is  the name of the service as specified
                  in the master.cf file.  The default limit is  taken
                  from    the   default_destination_concurrency_limit
                  parameter.

           transport_destination_recipient_limit
                  Limit the number of recipients per message delivery
                  via  this mail delivery transport. transport is the
                  name of the service as specified in  the  master.cf
                  file.    The   default  limit  is  taken  from  the
                  default_destination_recipient_limit parameter.

                  This parameter  becomes  significant  if  the  LMTP
                  client  is  used  for  local  delivery.   Some LMTP
                  servers can optimize delivery of the  same  message
                  to multiple recipients. The default limit for local
                  mail delivery is 1.

                  Setting  this  parameter  to  0  will  lead  to  an
                  unbounded  number of recipients per delivery.  How-
                  ever, this could be risky since  it  may  make  the
                  machine  vulnerable  to running out of resources if
                  messages are encountered with an inordinate  number
                  of  recipients.   Exercise  care  when setting this
                  parameter.

    Timeout controls
           The default time unit is seconds; an  explicit  time  unit
           can  be  specified by appending a one-letter suffix to the
           value: s (seconds), m (minutes), h (hours), d (days) or  w
           (weeks).

           lmtp_connect_timeout
                  Timeout  for  opening  a  connection  to  the  LMTP
                  server.  If no connection can be  made  within  the
                  deadline, the message is deferred.

           lmtp_lhlo_timeout
                  Timeout  for  sending  the  LHLO  command,  and for
                  receiving the server response.

           lmtp_mail_timeout
                  Timeout for sending the MAIL FROM command, and  for
                  receiving the server response.

           lmtp_rcpt_timeout
                  Timeout  for  sending  the RCPT TO command, and for
                  receiving the server response.

           lmtp_data_init_timeout
                  Timeout for  sending  the  DATA  command,  and  for
                  receiving the server response.

           lmtp_data_xfer_timeout
                  Timeout for sending the message content.

           lmtp_data_done_timeout
                  Timeout  for  sending  the  "."  command,  and  for
                  receiving the server response. When no response  is
                  received,  a warning is logged that the mail may be
                  delivered multiple times.

           lmtp_rset_timeout
                  Timeout for  sending  the  RSET  command,  and  for
                  receiving the server response.

           lmtp_quit_timeout
                  Timeout  for  sending  the  QUIT  command,  and for
                  receiving the server response.

    SEE ALSO
           bounce(8) non-delivery status reports
           local(8) local mail delivery
           master(8) process manager
           qmgr(8) queue manager
           services(4) Internet services and aliases
           spawn(8) auxiliary command spawner
           syslogd(8) system logging

    LICENSE
           The Secure Mailer license must be  distributed  with  this
           software.

    AUTHOR(S)
           Wietse Venema
           IBM T.J. Watson Research
           P.O. Box 704
           Yorktown Heights, NY 10598, USA

           Alterations for LMTP by:
           Philip A. Prindeville
           Mirapoint, Inc.
           USA.

           Additional work on LMTP by:
           Amos Gouaux
           University of Texas at Dallas
           P.O. Box 830688, MC34
           Richardson, TX 75083, USA

                                                              LMTP(8)