Tracking Email Question????

[WebCreatorSoft]

I've recently had a big problem with spammers using misdirected bounces to send spam on Plesk 7.0 server.. I just upgraded to 7.5 mostly for the 'reject' mail to non-existent users feature. When I do a ps -ax, I see things like:

27998 ? S 0:00 qmail-remote westolympian.com [email protected]
27999 ? S 0:00 qmail-remote westolympian.com [email protected]
28000 ? S 0:00 qmail-remote westolympian.com [email protected]
28001 ? S 0:00 qmail-remote westolympian.com [email protected]
28002 ? S 0:00 qmail-remote westolympian.com [email protected]

I can't recognize any corresponding entries in maillog, how can I determine the source of these messages (I don't host the domain westolympian.com ).

Also, how to verify that messages to non-existent users is actually being rejected. How to verify the MAPS is working correctly (can't see any log entries for either of these)..