SMTPD(8)                    System Manager's Manual                   SMTPD(8)

NAME
     smtpd - Simple Mail Transfer Protocol (SMTP) daemon

SYNOPSIS
     smtpd [-dFhnv] [-D macro=value] [-f file] [-P system] [-T trace]

DESCRIPTION
     smtpd is a Simple Mail Transfer Protocol (SMTP) daemon which can be used
     as a machine's primary mail system.  smtpd can listen on a network
     interface and handle SMTP transactions; it can also be fed messages
     through the standard sendmail(8) interface.  It can relay messages
     through remote mail transfer agents or store them locally using either
     the mbox or maildir format.  This implementation supports SMTP as defined
     by RFC 5321 as well as several extensions.  A running smtpd can be
     controlled through smtpctl(8).

     The options are as follows:

     -D macro=value
             Define macro to be set to value on the command line.  Overrides
             the definition of macro in the configuration file.

     -d      Do not daemonize.  If this option is specified, smtpd will run in
             the foreground and log to stderr.

     -F      Do not daemonize.  If this option is specified, smtpd will run in
             the foreground and log to syslogd(8).

     -f file
             Specify an alternative configuration file.

     -h      Display version and usage.

     -n      Configtest mode.  Only check the configuration file for validity.

     -P system
             Pause a specific subsystem at startup.  Normal operation can be
             resumed using smtpctl(8).  This option can be used multiple
             times.  The accepted values are:

             mda      Do not schedule local deliveries.
             mta      Do not schedule remote transfers.
             smtp     Do not listen on SMTP sockets.

     -T trace
             Enables real-time tracing at startup.  Normal operation can be
             resumed using smtpctl(8).  This option can be used multiple
             times.  The accepted values are:

             o   imsg
             o   io
             o   smtp (incoming sessions)
             o   filters
             o   transfer (outgoing sessions)
             o   bounce
             o   scheduler
             o   expand (aliases/virtual/forward expansion)
             o   lookup (user/credentials lookups)
             o   stat
             o   rules (matched by incoming sessions)
             o   mproc
             o   all

     -v      Produce more verbose output.

FILES
     /etc/smtpd/mailname       Alternate server name to use.
     /etc/smtpd/smtpd.conf     Default smtpd configuration file.
     /run/smtpd.sock           UNIX-domain socket used for communication with
                               smtpctl(8).
     /var/spool/smtpd/         Spool directories for mail during processing.
     ~/.forward                User email forwarding information.

SEE ALSO
     forward(5), smtpd.conf(5), mailwrapper(8), smtpctl(8)

STANDARDS
     J. Klensin, Simple Mail Transfer Protocol, RFC 5321, October 2008.

HISTORY
     The smtpd program first appeared in OpenBSD 4.6.

Linux 6.8.2-arch2-1              March 2, 2023             Linux 6.8.2-arch2-1