目录一．引言..............................................................................................................................................................................1三．邮件服务器安全的简介..............................................................................................................................................2（一）邮件服务器安全的原理.....................................................................................................................................2（二）邮件服务器安全的类型.....................................................................................................................................2三．搭建DNS服务器..........................................................................................................................................................3（一）DNS的系统组成...................................................................................................................................................3（二）实验环境.............................................................................................................................................................4（三）搭建DNS服务器..................................................................................................................................................4四．搭建SENDMAIL邮件服务器.........................................................................................................................................11（一）Sendmail简介...................................................................................................................................................11（二）Sendmail邮件服务器的优缺点.......................................................................................................................11（三）搭建Sendmail邮件服务器..............................................................................................................................12（四）测试邮件的发送...............................................................................................................................................15六．DNS的负载均衡.........................................................................................................................................................19（一）基于DNS的负载均衡........................................................................................................................................19（二）用客户机测试DNS服务器................................................................................................................................19（三）测试DNS的负载均衡........................................................................................................................................21七．SENDMAIL邮件服务器安全策略的实现......................................................................................................................21（一）关闭Sendmail的Relay功能..........................................................................................................................21（二）在Sendmail中实时黑名单过滤......................................................................................................................22（三）配置Access文件............................................
