Simple but working solution (Score 1)

I use a mail client with Bayesian filter which I configured so that every unfiltered mail goes into the basket immediately. For every kind of mail which shouldn't be there (e.g. mails from known friends or new customers) I define a new rule. Most mail clients can be configured so that the basket is flushed on every exit. This solution is simple but it works at least for me. At the beginning I had some work to define all the rules but now it works for _every_ spam so far, regardless which tactics the spammers use.