.TH LMTP 8 .ad .fi .SH NAME lmtp \- Postfix local delivery via LMTP .SH SYNOPSIS .na .nf \fBlmtp\fR [generic Postfix daemon options] .SH DESCRIPTION .ad .fi 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 recipient information. This program expects to be run from the \fBmaster\fR(8) process manager. The LMTP client updates the queue file and marks recipients 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 \fBbounce\fR(8) or \fBdefer\fR(8) daemon as appropriate. The LMTP client connects to the destination specified in the message delivery request. The destination, usually specified in the Postfix \fBtransport\fR(5) table, has the form: .IP \fBunix\fR:\fIpathname\fR Connect to the local UNIX-domain server that is bound to the specified \fIpathname\fR. If the process runs chrooted, an absolute pathname is interpreted relative to the changed root directory. .IP "\fBinet\fR:\fIhost\fR, \fBinet\fB:\fIhost\fR:\fIport\fR (symbolic host)" .IP "\fBinet\fR:[\fIaddr\fR], \fBinet\fR:[\fIaddr\fR]:\fIport\fR (numeric host)" Connect to the specified IPV4 TCP port on the specified local or remote host. If no port is specified, connect to the port defined as \fBlmtp\fR in \fBservices\fR(4). If no such service is found, the \fBlmtp_tcp_port\fR 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. .PP If neither \fBunix:\fR nor \fBinet:\fR are specified, \fBinet:\fR is assumed. .SH SECURITY .na .nf .ad .fi 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. .SH STANDARDS .na .nf 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) .SH DIAGNOSTICS .ad .fi Problems and transactions are logged to \fBsyslogd\fR(8). Corrupted message files are marked so that the queue manager can move them to the \fBcorrupt\fR queue for further inspection. Depending on the setting of the \fBnotify_classes\fR parameter, the postmaster is notified of bounces, protocol problems, and of other trouble. .SH BUGS .ad .fi .SH CONFIGURATION PARAMETERS .na .nf .ad .fi The following \fBmain.cf\fR parameters are especially relevant to this program. See the Postfix \fBmain.cf\fR file for syntax details and for default values. Use the \fBpostfix reload\fR command after a configuration change. .SH Miscellaneous .ad .fi .IP \fBdebug_peer_level\fR Verbose logging level increment for hosts that match a pattern in the \fBdebug_peer_list\fR parameter. .IP \fBdebug_peer_list\fR List of domain or network patterns. When a remote host matches a pattern, increase the verbose logging level by the amount specified in the \fBdebug_peer_level\fR parameter. .IP \fBerror_notice_recipient\fR Recipient of protocol/policy/resource/software error notices. .IP \fBnotify_classes\fR When this parameter includes the \fBprotocol\fR class, send mail to the postmaster with transcripts of LMTP sessions with protocol errors. .IP \fBlmtp_skip_quit_response\fR Do not wait for the server response after sending QUIT. .IP \fBlmtp_tcp_port\fR The TCP port to be used when connecting to a LMTP server. Used as backup if the \fBlmtp\fR service is not found in \fBservices\fR(4). .SH "Authentication controls" .IP \fBlmtp_sasl_auth_enable\fR Enable per-session authentication as per RFC 2554 (SASL). By default, Postfix is built without SASL support. .IP \fBlmtp_sasl_password_maps\fR Lookup tables with per-host or domain \fIname\fR:\fIpassword\fR entries. No entry for a host means no attempt to authenticate. .IP \fBlmtp_sasl_security_options\fR Zero or more of the following. .RS .IP \fBnoplaintext\fR Disallow authentication methods that use plaintext passwords. .IP \fBnoactive\fR Disallow authentication methods that are vulnerable to non-dictionary active attacks. .IP \fBnodictionary\fR Disallow authentication methods that are vulnerable to passive dictionary attack. .IP \fBnoanonymous\fR Disallow anonymous logins. .RE .SH "Resource controls" .ad .fi .IP \fBlmtp_cache_connection\fR 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: .RS .IP \(bu The LMTP client idle time limit is reached. This limit is specified with the Postfix \fBmax_idle\fR configuration parameter. .IP \(bu A delivery request specifies a different destination than the one currently cached. .IP \(bu The per-process limit on the number of delivery requests is reached. This limit is specified with the Postfix \fBmax_use\fR configuration parameter. .IP \(bu Upon the onset of another delivery request, the LMTP server associated with the current session does not respond to the \fBRSET\fR command. .RE .IP \fItransport_\fBdestination_concurrency_limit\fR Limit the number of parallel deliveries to the same destination via this mail delivery transport. \fItransport\fR is the name of the service as specified in the \fBmaster.cf\fR file. The default limit is taken from the \fBdefault_destination_concurrency_limit\fR parameter. .IP \fItransport_\fBdestination_recipient_limit\fR Limit the number of recipients per message delivery via this mail delivery transport. \fItransport\fR is the name of the service as specified in the \fBmaster.cf\fR file. The default limit is taken from the \fBdefault_destination_recipient_limit\fR 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. However, 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. .SH "Timeout controls" .ad .fi .PP 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). .IP \fBlmtp_connect_timeout\fR Timeout for opening a connection to the LMTP server. If no connection can be made within the deadline, the message is deferred. .IP \fBlmtp_lhlo_timeout\fR Timeout for sending the \fBLHLO\fR command, and for receiving the server response. .IP \fBlmtp_mail_timeout\fR Timeout for sending the \fBMAIL FROM\fR command, and for receiving the server response. .IP \fBlmtp_rcpt_timeout\fR Timeout for sending the \fBRCPT TO\fR command, and for receiving the server response. .IP \fBlmtp_data_init_timeout\fR Timeout for sending the \fBDATA\fR command, and for receiving the server response. .IP \fBlmtp_data_xfer_timeout\fR Timeout for sending the message content. .IP \fBlmtp_data_done_timeout\fR Timeout for sending the "\fB.\fR" command, and for receiving the server response. When no response is received, a warning is logged that the mail may be delivered multiple times. .IP \fBlmtp_rset_timeout\fR Timeout for sending the \fBRSET\fR command, and for receiving the server response. .IP \fBlmtp_quit_timeout\fR Timeout for sending the \fBQUIT\fR command, and for receiving the server response. .SH SEE ALSO .na .nf 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 .SH LICENSE .na .nf .ad .fi The Secure Mailer license must be distributed with this software. .SH AUTHOR(S) .na .nf 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