Email takes on an ever greater role in personal and business communication . mail user agent ( mua ) is a client program that allows one to send and receive email Email是internet上进行通讯最常用的方式，而邮件用户代理( mua )是用户用来发送或接收email的客户端程序。
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The user can now use the filtering feature of his or her favorite mail user agent to sweep these tagged spam messages to a " junk mail " folder or to delete them 现在用户可以使用他或她喜欢的邮件用户代理的过滤功能来将这些带标记的垃圾邮件消息扫除到“垃圾邮件”文件夹或删除它们。
