阐述动态域名解析、E-mail 工作原理,重点介绍SMTP 及安全认证,在linux 下用动态域名解析与Sendmail+SASL 构建安全、经济而实用的动态邮件服务器。为中小企业、部门架建小型服务器提供一个参考方案。 关键字:动态域名解析,SMTP,Sendmail,SASL Abstract:This paper describes DDNS and the theory of E-mail,takes SMTP and security authentication as the focal point.It offer a referenced scheme for middle or mini corporations or departments about constructing a security,economical and applied "Dynamic" mail server by DDNS and Sendmail+SASL in linux. key words:DDNS,SMTP,Sendmail,SASL