I am running Postfix on a linux box with a couple hundred local users with mailboxes.
Is there a way to monitor all incoming connections (SMTP) to the Postfix service? I.e. a live stream of "IP Address x.x.x.x just connected to the Postfix server" and "IP Address y.y.y.y just disconnected" ?
I want to monitor all incoming connections so I can look for trends of the same IP address attempting to send multiple spam to my users or possibly trying to relay (it's not an open relay btw!).
Just dumping all connections and disconnections, with IP address listed, to a text file or syslog would be perfect. Or possibly there is another, better way?