spamassassin problem

[Andrew Doades]

I have a ubuntu server 7.10 running and processing a lot of mail, so I 
recently decided to move onto Spamassassin to filter my spam away but 
event after several weeks of moving, sa-learn ing, and google searching, 
I can't find what the problem is...

Spamassassin will not mark messages as spam, it's set to put 
*****SPAM***** in the header, but nothing, no errors in the log!

Please help!
Andrew