sovereign/roles/monitoring/files/etc_monit_conf.d_postfix

check process postfix with pidfile /var/spool/postfix/pid/master.pid
  group mail
  start program = "/bin/systemctl start postfix"
  stop program = "/bin/systemctl stop postfix"
  if failed port 25 protocol smtp then restart
  if 5 restarts within 5 cycles then timeout