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                     Example of the SMTP Procedure

         This SMTP example shows mail sent by Smith at host Alpha.ARPA,
         to Jones, Green, and Brown at host Beta.ARPA.  Here we assume
         that host Alpha contacts host Beta directly.

            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 .
            S: Blah blah blah...
            S: ...etc. etc. etc.
            S: .
            R: 250 OK

         The mail has now been accepted for Jones and Brown.  Green did
         not have a mailbox at host Beta.

                               Example 1

      -------------------------------------------------------------

















 

                                                                        
RFC 821                                                      August 1982
                                           Simple Mail Transfer Protocol



   3.2.  FORWARDING

      There are some cases where the destination information in the
      <forward-path> is incorrect, but the receiver-SMTP knows the
      correct destination.  In such cases, one of the following replies
      should be used to allow the sender to contact the correct
      destination.

         251 User not local; will forward to <forward-path>

            This reply indicates that the receiver-SMTP knows the user's
            mailbox is on another host and indicates the correct
            forward-path to use in the future.  Note that either the
            host or user or both may be different.  The receiver takes
            responsibility for delivering the message.

         551 User not local; please try <forward-path>

            This reply indicates that the receiver-SMTP knows the user's
            mailbox is on another host and indicates the correct
            forward-path to use.  Note that either the host or user or
            both may be different.  The receiver refuses to accept mail
            for this user, and the sender must either redirect the mail
            according to the information provided or return an error
            response to the originating user.

      Example 2 illustrates the use of these responses.

      -------------------------------------------------------------

                         Example of Forwarding

      Either

      S: RCPT TO:<Postel@USC-ISI.ARPA>
      R: 251 User not local; will forward to <Postel@USC-ISIF.ARPA>

      Or