% diagram 5

\verbatim
To: <reply-to|from>
cc: <??to|cc><to>,<cc>
Fcc: +outbox
Fcc: <??fcc><fcc>
Subject: <??subject>Re: <subject>
In-reply-to: <??date><??message-id>Your message of <date>.
	     <message-id>
In-reply-to: <??date><!message-id>Your message of <date>.
Reply-To: /dev/null
--------

                          \
                         *-XXX
                          /   XX
                                X
                                  X
                                   X
                                   X
                                   X
                               IIIIIIIII
                               IIIIIIIII
                               IIIIIIIII
                               IIIIIIIII
                               XXXXXXXXX
                        XXXXXXXXXXXXXXXXXXXXXXX
                     XXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                  XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
               XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
              XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
            XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
           XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
          XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
         XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
         XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
         XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
          XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
           XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
            XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
              XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
               XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                  XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                     XXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                        XXXXXXXXXXXXXXXXXXXXXXX
                               XXXXXXXXX
?endverbatim