What do they do? How do they work? Which one is right for me? By Alan Hearnshaw Spam is a very real problem that many people have to deal with on a daily basis. For those that have decided to do something about it and start to investigate the options available in spam filtering, this article provides a brief introduction to your options and the types of spam filters available. Despite the bewildering array of spam filters available today, all claiming to the best one "of its kind" there are really just five filtering methodologies in general use today and all products rely on one, or a combination of these: