I ran across Spamato a couple of weeks ago and thought I’d give it a try. I had been using Thunderbird’s adaptive spam filter with a decent amount of success (in addition to enabling our corporate junk filter). What intrigued me about Spamato is the fact that there are six different filters that run at the same time. There is a bayesian filter, a collarborative multi-hash filter, two URL based filters that query different sites (Google and a collaborative site), a custom rule manager, and a collaborative filter where votes and a trust system come into play.
All these filters work together to decide if a particular message is spam or ham (spam = unwanted email, ham = wanted email). What I really liked, though, was the fact that there is a web server that gets installed that lets you configure everything, and had some nice statistics that show you what’s going on.
So, if you’re in the market for a new spam filter, definately check out Spamato!