[Unit] Description=Nullmailer relay-only MTA After=network.target RequiresMountsFor=/var/spool/nullmailer ConditionPathExists=/var/spool/nullmailer/queue Documentation=man:nullmailer(7) [Service] WorkingDirectory=/var/spool/nullmailer ExecStart=/usr/sbin/nullmailer-send User=mail Group=mail Restart=always SyslogFacility=mail [Install] WantedBy=multi-user.target