Subject: draft-ietf-drums-smtpupd-10.txt, section 4.5.3

From: Dan Wing <[email-masked]>
Date: Tue, 16 Mar 1999 18:58:07 -0800 (PST)

Section 4.5.3, "Sizes and Timeouts", says:

  [RFC-821] incorrectly listed the error where an SMTP server exhausts its
  implementation limit on the number of RCPT TO commands ("too many
  recipients") as having reply code 552.  The correct reply code for this
  condition is 452. Clients SHOULD treat a 552 code in this case as a
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  temporary, rather than permanent failure so the logic below works.
  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...
  If an SMTP server has an implementation limit on the number of RCPT TO
  commands and this limit is exhausted, it MUST use a response code of 
  452.  If the server has a configured site-policy limitation on the
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  number of RCPT TO commands, it MAY instead use a 5XX response code.
  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

If clients don't follow the Should of the first highlighted sentence,
they will bounce mail if the client is communicating with a server
that follows the May of the second highlighted sentence.

I don't understand if this wording is present for backwards compatability
with the mistake in RFC821 or for other reasons, so I can't quite suggest
suggested wording changes.

-Dan Wing