Trying to help friend NOT get caught by spamassassin

[Robert Moskowitz]

I have a friend that puts out a 'barter' list.  He acts as a 
clearinghouse for some equipment wholesalers.

He has been fighting getting tagged as spamming for some time and 
finally came to me for help.  I had helped some, but finally told him to 
add me to his distribution (he uses BCC lists; he has ~2000 
wholesalers).  I have spamassassin running with postfix and pretty much 
a default setup, and of course his notes got tagged as spam.  Below is 
what I pulled out of the headers.  Were do I go to learn what these mean 
and what he can do to 'clean up' his messages?

Oh, and I am looking at setting up a mailman server for him as an 
announce list.

Yes, score=10.206 tagged_above=2 required=4    tests=[BAYES_50=0.8, 
EXCUSE_REMOVE=3.299, FILL_THIS_FORM=0.001,    FILL_THIS_FORM_LONG=3.404, 
HTML_MESSAGE=0.001, LOTS_OF_MONEY=0.001,    MANY_SPAN_IN_TEXT=2.7, 
RCVD_IN_DNSWL_NONE=-0.0001] autolearn=no

Yes, score=8.856 tagged_above=2 required=4 tests=[AWL=1.350,    
BAYES_50=0.8, EXCUSE_REMOVE=3.299, FILL_THIS_FORM=0.001,    
FILL_THIS_FORM_LONG=3.404, HTML_MESSAGE=0.001, LOTS_OF_MONEY=0.001,    
RCVD_IN_DNSWL_NONE=-0.0001] autolearn=no