Not sure I understand the problem fully, however I have put an end to my issues with spam by adopting the SpamAssassin "proxy".
http://au2.spamassassin.org/index.html
The program is downloaded (built or source) and then run locally and has a built-in set of rules that can be modified and updated and that put spam into a user-specified "spam" mailbox/folder.
It is open source (but commercial packages are also available for those who prefer buying a name) and extremely reliable, works wonders for Windows under just about any email client (Eudora, Outlook, what have you..) and a hell of a lot of other platforms too.
Plenty of docs and help on website,
AFAIK it's the best spam killer around.
hope it helps,
C