Practical: A Spam Filter
Peter Seibel · Apress eBooks · 2005
In 2002 Paul Graham, having some time on his hands after selling Viaweb to Yahoo, wrote the essay “A Plan for Spam”1 that launched a minor revolution in spam-filtering technology. Prior to Graham’s article, most spam filters were written in terms of handcrafted rules: if a message has XXX in the subject, it’s probably a spam; if a message has a more than three or more words in a row in ALL CAPITAL LETTERS, it’s probably a spam. Graham spent several months trying to write such a rule-based filter before realizing it was fundamentally a soul-sucking task.