本文出自: 作者: (2001-11-23 09:08:00)
第二步：转发主机到目的主机

R: 220 BBN-VAX.ARPA Simple Mail Transfer Service Ready

S: HELO USC-ISIE.ARPA

R: 250 BBN-VAX.ARPA

　

S: MAIL FROM:<@USC-ISIE.ARPA:JQP@MIT-AI.ARPA>

R: 250 OK

　

S: RCPT TO:<Jones@BBN-VAX.ARPA>

R: 250 OK

　

S: DATA

R: 354 Start mail input; end with <CRLF>.<CRLF>

S: Received: from MIT-AI.ARPA by USC-ISIE.ARPA ;

2 Nov 81 22:40:10 UT

S: Date: 2 Nov 81 22:33:44

S: From: John Q. Public <JQP@MIT-AI.ARPA>

S: Subject: The Next Meeting of the Board

S: To: Jones@BBN-Vax.ARPA

S:

S: Bill:

S: The next meeting of the board of directors will be

S: on Tuesday.

S: John.

S: .

R: 250 OK

　

S: QUIT

R: 221 USC-ISIE.ARPA Service closing transmission channel

  

确认和发送

R: 220 SU-SCORE.ARPA Simple Mail Transfer Service Ready

S: HELO MIT-MC.ARPA

R: 250 SU-SCORE.ARPA

　

S: VRFY Crispin

R: 250 Mark Crispin <Admin.MRC@SU-SCORE.ARPA>

　

S: SEND FROM:<EAK@MIT-MC.ARPA>

R: 250 OK

　

S: RCPT TO:<Admin.MRC@SU-SCORE.ARPA>

R: 250 OK

　

S: DATA

R: 354 Start mail input; end with <CRLF>.<CRLF>

S: Blah blah blah...

S: ...etc. etc. etc.

S: .

R: 250 OK

　

S: QUIT

R: 221 SU-SCORE.ARPA Service closing transmission channel

  

获得和发送邮件 首先确定用户名，然后尝试将邮件发送到用户终端，
当它失败时，发送到用户邮箱。

R: 220 SU-SCORE.ARPA Simple Mail Transfer Service Ready

S: HELO MIT-MC.ARPA

R: 250 SU-SCORE.ARPA

　

S: VRFY Crispin

R: 250 Mark Crispin <Admin.MRC@SU-SCORE.ARPA>

　

S: SEND FROM:<EAK@MIT-MC.ARPA>

R: 250 OK

　

S: RCPT TO:<Admin.MRC@SU-SCORE.ARPA>

R: 450 User not active now

　

S: RSET

R: 250 OK

　

S: MAIL FROM:<EAK@MIT-MC.ARPA>

R: 250 OK

　

S: RCPT TO:<Admin.MRC@SU-SCORE.ARPA>

R: 250 OK

　

S: DATA

R: 354 Start mail input; end with <CRLF>.<CRLF>

S: Blah blah blah...

S: ...etc. etc. etc.

S: .

R: 250 OK

　

S: QUIT

R: 221 SU-SCORE.ARPA Service closing transmission channel

  

上述问题的更有效的作法  

R: 220 SU-SCORE.ARPA Simple Mail Transfer Service Ready

S: HELO MIT-MC.ARPA

R: 250 SU-SCORE.ARPA

　

S: VRFY Crispin

R: 250 Mark Crispin <Admin.MRC@SU-SCORE.ARPA>

　

S: SOML FROM:<EAK@MIT-MC.ARPA>

R: 250 OK

　

S: RCPT TO:<Admin.MRC@SU-SCORE.ARPA>

R: 250 User not active now, so will do mail.

　

S: DATA

R: 354 Start mail input; end with <CRLF>.<CRLF>

S: Blah blah blah...

S: ...etc. etc. etc.

S: .

R: 250 OK

　

S: QUIT

R: 221 SU-SCORE.ARPA Service closing transmission channel

  

　　邮件列表 首先，两个邮件列表中的每一个在不同主机的不同会话上扩展，
然后，通过转发主机向列表上的用户发送邮件。

第一步：扩展第一个列表

R: 220 MIT-AI.ARPA Simple Mail Transfer Service Ready

S: HELO SU-SCORE.ARPA

R: 250 MIT-AI.ARPA

　

S: EXPN Example-People

R: 250-<ABC@MIT-MC.ARPA>

R: 250-Fred Fonebone <Fonebone@USC-ISIQ.ARPA>

R: 250-Xenon Y. Zither <XYZ@MIT-AI.ARPA>

R: 250-Quincy Smith <@USC-ISIF.ARPA