...
>Now I would like to know if there are any off campus users still using
>port 25, but have not found a way of putting this into the log, so if
>anybody has any suggestions on that front I would be very grateful.
Setting:
log_selector = +incoming_interface
in your main configuration should give you this. From section 45.15
of the fine manual:
incoming_interface: The interface on which a message was received
is added to the "<=" line as an IP address in square brackets,
tagged by I= and followed by a colon and the port number. The local
interface and port are also added to other SMTP log lines, for
example "SMTP connection from", and to rejection lines.