180    __  ___ _____________________________ Internet

     , 
  .      -
 Smith,  "Alpha.ARPA"   "Beta.ARPA".
^> <>' Vi ^^ ?^ -  -. S 
 SMTP, R   SMTP).

S MAIL FROM:<Smith@Alpha.ARPA>

R 250 OK

S RCPT TO:<Jones@Beta.ARPA>

R 250 OK

S RCPT TO:<Green@Beta.ARPA>

R 550 No such user here

S RCPT TO:<Brown@Beta.ARPA>

R 250 OK

S DATA

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

S hey hey hey...

S ... how do you do, Beta ?

S <CRLF>.<CRLF>

R 250 OK

    SMTP-,   -
 Jones  Brown,    Green    
 Beta.

  ,     (<forward-path>) 
      ,   SMTP
  .   SMTP    -
 SMTP  :

 257 User not local; will forward to <forward-path>.   
 ,   SMTP    -
  <forward-path>    
 .

 557 User not local; please try <forward-path>.    -
,   SMTP     
  <forward-path>,       -
     .

,       :

S: RCPT :<Green@Beta.ARPA>
R: 251 User not local; will forward to <Green@Batman.ARPA>



S: RCPT TO:<Green@Beta.ARPA>
R: 551 User not local; please try <White@Gamma.ARPA>