Probability rules
I have moved over to spamprobe for all my spam filtering needs. It’s an implementation of Paul Graham’s Bayesian spam detection algorithm, which detects spam based on word frequency analysis. It requires some training before it works well; you have to feed it a collection of a couple of hundred good messages and a couple of hundred spam messages so that it can build a table of spam words. Or, alternatively, you can train it over time and put up with false negatives and positives for a little while. But once you get those few hundred messages classified, you’re golden. ...