JunkMatcher

I guard my personal email addresses like they are my children, but every once and a while a little spam still sneaks thru. Mail.app does have some junk mail software, but it never hurts to have more. Especially one that is well built. JunkMatcher is a very good solution that integrates tightly with Mail.app.

From the Developer’s site:
It filters spam by conducting a wealth of tests over emails. Two types of tests are available: property tests can detect general characteristics of spam using techniques such as naive Bayesian filtering (thanks to SpamBayes) and blacklist lookup (checking if a message was sent from a spamming IP address), and pattern tests can spot keywords such as “v1ägra” or “\/Iagr á” by using patterns written in regular expressions, a very powerful language designed just for that – to describe patterns.

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