I've had some serious spam issues with my local postfix installation, until I found out that there was a postfix user wich was allowed to relay mails (I still don't know why this was possible in the first place, as relaying was closed for the whole server)..
I disallowed submitting mails for this user.
Anyway, my problem now is to figure out the IP address which still tries to connect to my server and to relay mails.
The log (mail.info and mail.err) shows this:
Jan 5 15:16:29 mailservername postfix/sendmail: fatal: User username(12345) is not allowed to submit mail
But it doesn't log an IP address anywhere.
Can someone tell me how to log that IP address?
Oh and if someone has an idea why a single user can relay mails despite the fact that relaying is closed, I'd be very grateful, too :)
Thanks in advance and best, Julian