wilsonweb.com gives you some hints how to get off a spammer Blacklist.

POPFile is a collection of perl scripts that works as a big filter / organizer for email. It uses the same filtering mechanism as Apple’s Mail and the equally essential SpamSieve (“bayesian” filtering), but allows you to create all kinds of “buckets” for your email. POPFile can then add an email header or prefix to the subject which can be used as a filter rule in your email client.