I don't know spamassassin's exact set up, but usually procmail spam filters read an email message from standard input and produce an exit code that tells you if the message is spam or not.
So from the Python side, it should be as easy as running whatever the command is (a quick googling suggests it is "sa-filter"), feeding it the message on stdin, and capturing the exit code. Have a look at Python's os.system, os.popen2, or os.popen3 fuctions. It may also be the case that the filter emits a modified version of the email on stdout containing spam-filter related headers. Also, I'd recommend spambayes above spamassassin. Spambayes is a statistical approach as opposed to Spamassassin's rule-based system*, and for bonus point's it's written in Python. * at this point someone will probably chime in saying it's possible to rig spamassassin with a bayesian filter... probably so. I haven't looked at it in years. -- http://mail.python.org/mailman/listinfo/python-list
