From Bryan Hughes, Mon Mar 7 11:01:54 2005
The way to use spamassassin to work with your user_prefs the way it is specified on the spamassassin site is to invoke spamassassin from procmail.
This can be done by adding
:0fw: spamassassin.lock |/usr/bin/spamassassin
to the top of your .procmailrc file.
This will rewrite your headers and do everything else you specified in your .spamassassin/user_prefs file.
More detailed instructions and information on this can be found in the TCC Help System document on spamassassin.
For more on procmail see www.procmail.org.