NAME

       mta-sts-daemon - provide MTA-STS policy to Postfix as policy map

SYNOPSIS

       mta-sts-daemon [OPTION]...

DESCRIPTION

       This daemon opens a socket where Postfix can query and retrieve the MTA-STS policy for a domain. The
       configuration file is described in mta-sts-daemon.yml(5).

       MTA-STS, specified in RFC 8461 [0], is a security standard for email servers. When a site configures
       MTA-STS, other mail servers can require the successful authentication of that site when forwarding mail
       there.

OPTIONS

       -h, --help
           show a help message and exit

       -v, --verbosity VERBOSITY
           set log verbosity level: debug, info (default), warn, error, or fatal.

       -c, --config FILE
           config file location (default: /etc/mta-sts-daemon.yml)

       -g, --group GROUP
           change eGID to this group (default: none)

       -l, --logfile FILE
           log file location (default: none)

       -p, --pidfile PIDFILE
           name of the file to write the current pid to (default: none)

       -u, --user USER
           change eUID to this user (default: none)

       --disable-uvloop
           do not use uvloop even if it is available (default: enabled if available)

EXAMPLES

       Configure Postfix in /etc/postfix/main.cf:

           smtp_tls_policy_maps = socketmap:inet:127.0.0.1:8461:postfix
           smtp_tls_CApath = /etc/ssl/certs/

       Reload Postfix. Then verify it works:

       /usr/sbin/postmap -q dismail.de socketmap:inet:127.0.0.1:8461:postfix

       This configuration overrides DANE TLS authentication. If you wish to meet the requirement of RFC 8461,
       section 2, you should list a DANE policy resolver (or a static lookup table for domains known to
       implement both MTA-STS & DANE) before mta-sts-daemon in smtp_tls_policy_maps.

SEE ALSO

       mta-sts-query(1), mta-sts-daemon.yml(5)

NOTES

       0.
           SMTP MTA Strict Transport Security (MTA-STS): https://tools.ietf.org/html/rfc8461

postfix-mta-sts-resolver                           2025-03-10                                  MTA-STS-DAEMON(1)