NAME

       msmtpd - A minimal SMTP server

SYNOPSIS

       msmtpd [option...]

DESCRIPTION

       Msmtpd  is  a  minimal SMTP server that pipes mails to msmtp (or some other program) for delivery.  It is
       intended to be used with system services that expect an SMTP server on  the  local  host  and  cannot  be
       configured to use the sendmail interface that msmtp provides.
       Msmtpd  handles  local SMTP clients. It listens on 127.0.0.1 port 25 by default, but can also run without
       its own network sockets in inetd mode, where it handles a single SMTP session on standard input / output.
       In the string that defines the command that msmtpd pipes each mail to, the first occurrence of %F will be
       replaced with the envelope from address. Furthermore, all recipients of the  mail  will  be  appended  as
       arguments. The command must not write to standard output, as that would mess up the SMTP session.
       If  the  command  that  the  mail is piped to reports an error, this is typically reported as a permanent
       failure by msmtpd (SMTP server return code 554). The command can optionally signal  temporary  errors  by
       using  return  codes  defined  in  sysexits.h,  e.g.  75  for EX_TEMPFAIL. These will then be reported as
       temporary failures by msmtpd (SMTP server return code 451), which  means  the  client  should  try  again
       later.
       Only  run  msmtpd  if  you know you need it. Only use a local interface to listen on. Take care to run it
       with correct user rights and permissions (e.g. use CAP_NET_BIND_SERVICE to bind to  port  25  instead  of
       running  as root, or use systemd with inetd service capabilities). Be aware that the pipe command will be
       run as the same user that msmtpd runs as.

OPTIONS

       --version
              Print version information

       --help Print help

       --inetd
              Start single SMTP session on stdin/stdout

       --interface=ip
              Listen on the given IPv6 or IPv4 address instead of 127.0.0.1

       --port=number
              Listen on the given port number instead of 25

       --command=cmd
              Pipe mails to cmd instead of msmtp

EXAMPLES

       Managing msmtpd with start-stop-daemon
       # start msmtpd
       start-stop-daemon --start --pidfile /var/run/msmtpd.pid --make-pidfile --chuid msmtpd --background --exec
       /usr/local/bin/msmtpd -- --command '/usr/local/bin/msmtp -f %F'
       # stop msmtpd
       start-stop-daemon --stop  --pidfile /var/run/msmtpd.pid --remove-pidfile --quiet --signal TERM

SEE ALSO

       msmtp(1)

                                                     2021-08                                           MSMTPD(1)