Current approaches aren't working; even though home users and many companies started filtering their email two years age, the overall amount of junk mail has ballooned exponentially.

目前采用的方法都不可行。虽然两年前家庭用户以及许多公司用户都已开始使用邮件过滤功能，但垃圾邮件的总量还是呈几何指数增长。

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The authors analyze the essence of some existing algorithms of junk E-mail filtering rules and give the way to represent an E-mail as a transaction.

该文对现有电子邮件系统中存在的安全性、垃圾邮件、邮件分类、信箱命名资源等问题进行了分析。

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