经常在测试的时候需要自己构造信头, 把telnet发邮件的过程记下来吧, 不知道有什么好工具可以代替....

liujie# telnet 202.108.3.230 25        //连接mx服务器的25端口
Trying 202.108.3.230...
Connected to 202.108.3.230.
Escape character is '^]'.
220 mx3-24.sinamail.sina.com.cn ESMTP Postfix (Postfix Rules!)
helo xx.com                            //申明自己的测试域
250 mx3-24.sinamail.sina.com.cn
mail from:<xxx@xx.com>                 //发件地址
250 2.1.0 Ok
rcpt to:<test1239@sina.com>            //接收地址
250 2.1.5 Ok
data                                   //邮件开始
354 End data with <CR><LF>.<CR><LF>
From:xxx@xx.com                        //和下面几行都是构造信头
To:test1239@sina.com
Subject:aaaaaaa
Date:Mon, 16 June 2008 14:50:55 +0800
MIME-Version:1.0
Content-Type:multipart/alternative
sssssssssssssssss
.                                      //邮件结束
250 2.0.0 Ok: queued as B216334DBF0
quit                                   //断开连接
221 2.0.0 Bye
Connection closed by foreign host.