This might work to configure monit on Debian (Jessie) to monitor postsrsd. check process postsrsd matching “/usr/sbin/postsrsd” group postsrsd start program = “/etc/init.d/postsrsd start” stop program = “/etc/init.d/postsrsd stop” if failed host localhost port 10001 then restart if failed host localhost port 10002 then restart
A python script which can be used as a Postfix content_filter to headers email going through it … (example shows changing the Subject).
One server I poke around on, has a number of postfix instances (see: postmulti). Interestingly, one instance was logging things like : Oct 26 22:02:05 mail postfix-blah/smtpd: connect from unknown[18.104.22.168] Oct 26 22:02:05 mail postfix-blah/smtpd: CA9292EE2C0: client=unknown[22.214.171.124]