Flow-based anti-spam

Approximately 40% of all email in the Internet is spam, and its volume is growing rapidly. Blackhole list and mail filter are the main measures to defend the spam at present. But as a matter of fact, the situation of spam flooding tends to be more and more terrible. In this paper, we proposed a new technology of anti-spam based on flows, which could detect spam and abnormal email behaviors in the network, according to the type of email flows and their respective characteristics. First, the impacts of spam are introduced. The conception of flow and some relative definitions are given. Then three types of email flows and their judgment models are presented. And three cases we aimed at to resolve the spam are discussed. Finally, network measurement system, the platform of deploying the anti-spam, and the policy-based scheduling are introduced.