NAME

     smtpd — Simple Mail Transfer Protocol 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:

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

     -v      Produce more verbose output.

FILES

     /etc/mailname       Alternate server name to use.
     /etc/smtpd.conf     Default smtpd configuration file.
     /var/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.