Or

            S: VRFY Gourzenkyinplatz
            R: 553 User ambiguous.

                               Example 3

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


















 

                                                                        
August 1982                                                      RFC 821
Simple Mail Transfer Protocol                                           



      The case of expanding a mailbox list requires a multiline reply as
      shown in example 4.

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

                  Example of Expanding a Mailing List

         Either

            S: EXPN Example-People
            R: 250-Jon Postel <Postel@USC-ISIF.ARPA>
            R: 250-Fred Fonebone <Fonebone@USC-ISIQ.ARPA>
            R: 250-Sam Q. Smith <SQSmith@USC-ISIQ.ARPA>
            R: 250-Quincy Smith <@USC-ISIF.ARPA:Q-Smith@ISI-VAXA.ARPA>
            R: 250-<joe@foo-unix.ARPA>
            R: 250 <xyz@bar-unix.ARPA>

         Or

            S: EXPN Executive-Washroom-List
            R: 550 Access Denied to You.

                               Example 4

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

      The character string arguments of the VRFY and EXPN commands
      cannot be further restricted due to the variety of implementations
      of the user name and mailbox list concepts.  On some systems it
      may be appropriate for the argument of the EXPN command to be a
      file name for a file containing a mailing list, but again there is
      a variety of file naming conventions in the Internet.

      The VRFY and EXPN commands are not included in the minimum
      implementation (Section 4.5.1), and are not required to work
      across relays when they are implemented.














 

                                                                        
RFC 821                                                      August 1982
                                           Simple Mail Transfer Protocol



   3.4.  SENDING AND MAILING

      The main purpose of SMTP is to deliver messages to user's
      mailboxes.  A very similar service provided by some hosts is to
      deliver messages to user's terminals (provided the user is active
      on the host).  The delivery to the user's mailbox is called
      "mailing", the delivery to the user's terminal is called