#'以后的部分是我的注解，'>'表示输入，其它的为服务器的回应

rui@ubuntu-home:~$ telnet email.ustc.edu.cn 25
Trying 202.38.64.8...
Connected to email.ustc.edu.cn.
Escape character is '^]'.
220 ESMTP
> ehlo # Say 'hello'
250-AUTH=LOGIN PLAIN
250-AUTH LOGIN PLAIN
250-PIPELINING
250 8BITMIME
> auth login # SMTP服务器需要用户验证
334 VXNlcm5hbWU6 # B64编码的 Username:
> cxVd # B64编码的你的用户名，保密起见，这个是假的
334 UGFzc3dvcmQ6 # B64编码的　Password:
> ebgacd45 # B64编码的你的密码，保密起见，这个是假的
235 go ahead (eyou mta) (http://eyou.net _80)
> Mail From: <r...@ustc.edu.cn>
250 OK (eyou mta)
> RCPT To: <r01u...@gmail.com>
250 OK (eyou mta) (http://eyou.net _15000000)
> Data
354 go ahead (eyou mta)
> Subject: test from command line
> To: 51p...@gmail.com # 这个好像没什么用的
>
>
> nnd, test from telnet command line
>
>
> .
250 OK:has queued (eyou mta)
> quit
221 close connection (eyou mta)
Connection closed by foreign host.