filter.plx

filter.plx is a fairly rudimentry spam filtering system coded in perl. When a piece of email comes in, two separate sets of rules are executed, one batch on the message header, another on the body. Of the second batch, one of the rules is a list of regexes that are matched against the body of the letter. It's pretty configurable to those comfy with unix and perl. You can adjust the threshold, or individually disable various rules.