University of Calgary
Traditional spam detection systems either rely on content analysis to detect spam emails, or attempt to detect spammers before they send a message, (i.e., they rely on the origin of the message). In this paper, the authors introduce a third approach: they present a system for filtering spam that takes into account how messages are sent by spammers. More precisely, they focus on the email delivery mechanism, and analyze the communication at the SMTP protocol level. They introduce two complementary techniques as concrete instances of their new approach.