This is for use only by Linux power-users, as there is 
potential of losing mail if not implemented correctly.
Always test any changes you make.

To forward spam to a folder like ~/mail/spam create a folder 
named spam using pine then create a ~/.procmailrc file with 
exactly the following three lines: 

:0
* ^X-Spam-Status: Yes
mail/spam

If you want more control over the way spamassassin works then 
create a ~/.procmailrc file with contents:

INCLUDERC=/etc/mail/spamassassin/spamassassin-spamc.rc
:0
* ^X-Spam-Status: Yes
mail/spam

Then edit your ~/.spamassassin/user_prefs file. Sample contents for this file are:

required_hits   3
always_add_report 1

The required_hits variable sets the threshold for deciding if a message is spam. 
A higher number means fewer messages will be detected as spam.

The always_add_report varialble if set to 1 causes a report to be added to the header of
each email showing how the "hits" value is calculated. Otherwise this report is made only 
for spam emails.  

For more details on the ~/.spamassassin/user_prefs file type:

perldoc Mail::SpamAssassin::Conf

On the web also see:
http://spamassassin.apache.org/

You can find out how the "hits" were computed for each email message by looking at the email header.

You can fine-tune the hits scoring. 
For tests performed and details see:
http://spamassassin.apache.org/tests_3_0_x.html


This is not suggested, but one could force all detected spam to be irrecoverably 
deleted by using /dev/null rather than mail/spam in the above example. 

-- Russ