Study Of Spam-Filtering System Based On Multilayer Framework

The email filter is one of the key technologies of anti-Spam. Now there are mainly three types of email filter technology to deal with the Spam, which can be based on the contents, IP address and the head or envelope of the email. These methods all do good to the filtration of the Spam to a certain extent. The common way used in the Spam-filtering system is based on the contents mentioned above. But most of time it is not deployed transparently and is required to alter the structure of the network in existence when installing. Synchronously, it will cause the mail server to be the source of junk mail by the lack of identity authentication and user validation. The study of the Spam-filtering system developed a new way based on multilayer framework to resolve the disturbing Spam and the transparent gateway pattern is used.The filtering system adopts the Linux kernel tool named netfilter to dispose the Mail Gateway in the network layer, which need not to change the primary network structure when installing and transferring but needed in the mail-filtering system based on agent. As a result, the system is protected from Denial of Service attack.In the application layer POP3 Agent is used to implement SMTP authentication to settle the problem bored with the message transfer protocol. We wipe of the mail from guessed address by way of user list of mail server in-phase to confirm the user. What's more, the restrict of batch sending and RBL filter do more to the Spam.Key words filtering is carried out in the content layer. If the mail contains the preestablish key words, it will be insulated. At the same time, the filtering system uses...