1.\" $OpenBSD: smtpd.8,v 1.33 2023/03/02 17:09:53 jmc Exp $ 2.\" 3.\" Copyright (c) 2012, Eric Faurot <eric@openbsd.org> 4.\" Copyright (c) 2008, Gilles Chehade <gilles@poolp.org> 5.\" Copyright (c) 2008, Pierre-Yves Ritschard <pyr@openbsd.org> 6.\" 7.\" Permission to use, copy, modify, and distribute this software for any 8.\" purpose with or without fee is hereby granted, provided that the above 9.\" copyright notice and this permission notice appear in all copies. 10.\" 11.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 12.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 13.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 14.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 15.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 16.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 17.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 18.\" 19.Dd $Mdocdate: March 2 2023 $ 20.Dt SMTPD 8 21.Os 22.Sh NAME 23.Nm smtpd 24.Nd Simple Mail Transfer Protocol (SMTP) daemon 25.Sh SYNOPSIS 26.Nm 27.Op Fl dFhnv 28.Op Fl D Ar macro Ns = Ns Ar value 29.Op Fl f Ar file 30.Op Fl P Ar system 31.Op Fl T Ar trace 32.Sh DESCRIPTION 33.Nm 34is a Simple Mail Transfer Protocol 35.Pq SMTP 36daemon which can be used as a machine's primary mail system. 37.Nm 38can listen on a network interface and handle SMTP 39transactions; it can also be fed messages through the standard 40.Xr sendmail 8 41interface. 42It can relay messages through remote mail transfer agents or store them 43locally using either the mbox or maildir format. 44This implementation supports SMTP as defined by RFC 5321 as well as several 45extensions. 46A running 47.Nm 48can be controlled through 49.Xr smtpctl 8 . 50.Pp 51The options are as follows: 52.Bl -tag -width Ds 53.It Fl D Ar macro Ns = Ns Ar value 54Define 55.Ar macro 56to be set to 57.Ar value 58on the command line. 59Overrides the definition of 60.Ar macro 61in the configuration file. 62.It Fl d 63Do not daemonize. 64If this option is specified, 65.Nm 66will run in the foreground and log to 67.Em stderr . 68.It Fl F 69Do not daemonize. 70If this option is specified, 71.Nm 72will run in the foreground and log to 73.Xr syslogd 8 . 74.It Fl f Ar file 75Specify an alternative configuration file. 76.It Fl h 77Display version and usage. 78.It Fl n 79Configtest mode. 80Only check the configuration file for validity. 81.It Fl P Ar system 82Pause a specific subsystem at startup. 83Normal operation can be resumed using 84.Xr smtpctl 8 . 85This option can be used multiple times. 86The accepted values are: 87.Pp 88.Bl -tag -width "smtpXXX" -compact 89.It mda 90Do not schedule local deliveries. 91.It mta 92Do not schedule remote transfers. 93.It smtp 94Do not listen on SMTP sockets. 95.El 96.It Fl T Ar trace 97Enables real-time tracing at startup. 98Normal operation can be resumed using 99.Xr smtpctl 8 . 100This option can be used multiple times. 101The accepted values are: 102.Pp 103.Bl -bullet -compact 104.It 105imsg 106.It 107io 108.It 109smtp (incoming sessions) 110.It 111filters 112.It 113transfer (outgoing sessions) 114.It 115bounce 116.It 117scheduler 118.It 119expand (aliases/virtual/forward expansion) 120.It 121lookup (user/credentials lookups) 122.It 123stat 124.It 125rules (matched by incoming sessions) 126.It 127mproc 128.It 129all 130.El 131.It Fl v 132Produce more verbose output. 133.El 134.Sh FILES 135.Bl -tag -width "/etc/mail/smtpd.confXXX" -compact 136.It Pa /etc/mail/mailname 137Alternate server name to use. 138.It Pa /etc/mail/smtpd.conf 139Default 140.Nm 141configuration file. 142.It Pa /var/run/smtpd.sock 143.Ux Ns -domain 144socket used for communication with 145.Xr smtpctl 8 . 146.It Pa /var/spool/smtpd/ 147Spool directories for mail during processing. 148.It Pa ~/.forward 149User email forwarding information. 150.El 151.Sh SEE ALSO 152.Xr forward 5 , 153.Xr smtpd.conf 5 , 154.Xr mailwrapper 8 , 155.Xr smtpctl 8 156.Sh STANDARDS 157.Rs 158.%A J. Klensin 159.%D October 2008 160.%R RFC 5321 161.%T Simple Mail Transfer Protocol 162.Re 163.Sh HISTORY 164The 165.Nm 166program first appeared in 167.Ox 4.6 . 168