Mail Gateway Filtering System

E-mail is one of the most commonly-used tools for information exchange, and junk mails become an appendant which affects people's daily life, work and studies. Numbers of designs and researches on mail gateway are worked out to solve the problem of the flooding junk mails. However, they are all incomplete in some ways, such as failure to open to users, too much possession of internet resources, poor filtration of junk mails and etc. The paper, with the aim of solving all the problems, presents and designs a multi-filtering mail gateway based on different targets, structure and phases.The multi-filtering mail gateway, based on mail transmission principles and with different filtering methods, is designed to utilize internet resources comprehensively, guarantee filtering effect and speed up processing of junk mails in the process of mail transmission. At the mail server end, the system decides the connection through RT Black List & White List method, and then identifies mails through dialog to decide their real connection with the mail server; at the custom end, the system decides the submission of mails through Rule-based Scoring System and then analyzes the suspected mails with Bayesian Algorithm to decides their real submission to the assigned mailbox.The filtering mail gateway, with the consideration of the features of different transmission phases and different filtering methods, effectively utilizes internet resources and guarantee the filtering effects during the whole processing process, thus increasing filtering efficiency.