| 1. | In this paper , we design a layered spam filtering system mainly against the ways used by spam senders . the system is highly staged and expansible , including improved distributed black and white list , reverse dns and na ? ve bayes filtering technologies 本论文主要针对垃圾邮件发送者采用的方法,设计出一个层次化的垃圾邮件过滤系统,该系统具有高度的层次化,包括改进型分布式黑白名单,域名反向解析,以及na |