电子邮件过滤器的分析与设计

Analysis and Design of Electronic Mail Filter System

针对电子邮件应用日益广泛 ,邮件系统安全防护问题日益突出的现状 ,分析了邮件防护系统的关键———电子邮件过滤器在系统中的地位及其应用的必要性 ,提出了若干种邮件过滤器的结构方案及其在网络上的部署方案 ,并由此得出了相关结论 :基于SMTP过滤器的 ,具有基于规则的、附件扫描的、可清除恶意脚本的多重过滤能力的邮件过滤系统 ,是邮件安全防护系统的基础 .在此基础上 ,一方面对SMTP过滤器的功能进行扩充 ,使其成为独立的邮件服务器 ,直接满足用户的要求 ;另一方面 ,对于不支持SMTP的专用消息传递系统 ,研制对应的邮件过滤插件 ,只有这样 。

How to protect the E-mail system from invasion of computer viruses and mail bombs has become increasingly protruding due to the recently wide use of E-mail. In this paper, the necessity, functional structure and deployment strategy of electronic mail filter system are analyzed and discussed. Consequently, a relevant conclusion is drawn: building a SMTP mail filter system with capabilities of rule filtering, scanning attachments and removing harmful scripts is the base of a mail protection system. On one hand, we can extend its functions and make it an independent mail service system. On the other hand, we can make some filter plug-ins for some special message transfer systems that do not support SMTP. All of these make a total solution for mail protection system.