Hotmail Namespace Mining

[jissh]

I've just received a notice from MSN that one of my servers is namespace mining and they've blocked all emails from that server.

How do I go about finding the offending site and correcting the problem?

Any help would be appreciated.

[tillo]

Start by reading your /var/log/exim/mainlog file and look for multiple tries (and failures) of nonexistent @hotmail.* or @msn.* addresses. This will tell you which account is creating the spam or has a list of nonexistent addresses that make it similar to spam.