 guido takers how is esr s bogofilter packaged spamassassin the guido perl bayes filter advertised on slashdot dunno about the other tools but spamassassin is a breeze to incorporate into a procmail environment lots of people use it in many other ways for performance reasons many people run a spamd process and then invoke a small c program called spamc which shoots the message over to spamd and passes the result back out i think spambayes in incremental mode is probably fast enough to not require such tricks though i would consider changing the pickle to an anydbm file basic procmail usage goes something like this NUMBERfw spamassassin p NUMBER x spam status yes spam which just says run spamassassin p reinjecting its output into the processing stream if the resulting mail has a header which begins x spam status yes toss it into the folder indicated by the variable spam spamassassin also adds other headers as well which give you more detail about how its tests fared i d like to see spambayes operate in at least this way do its thing then return a message to stdout with a modified set of headers which further processing downstream can key on skip 