Sample SMTP Interaction(不用任何邮件客户端发邮件)

     S: 220 hamburger.edu

     C: HELO crepes.fr

     S: 250  Hello crepes.fr , pleased to meet you

     C: MAIL FROM: < [email protected] >

     S: 250 [email protected] ... Sender ok

     C: RCPT TO: < [email protected] >

     S: 250 [email protected] ... Recipient ok

     C: DATA

     S: 354 Enter mail, end with "." on a line by itself

     C: Do you like ketchup?

     C: How about pickles?

     C: .

     S: 250 Message accepted for delivery

     C: QUIT

     S: 221 hamburger.edu closing connection