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Re: Submit and HELO (was: Re: RFC2821bis-01 Issue 3: EHLO parameter)

2007-03-31 18:29:15


I think I understand the disconnect here.  The text in 2821 that
indicates that an SMTP server can be used for message submission
doesn't imply any of the properties of the Submission (port 587)
protocol.  SMTP/RFC2821 is nominally only used on port 25 while
Message Submission is nominally only used on part 587.  

So, from a protocol standpoint, one can use HELO on Port 25 for
initial message submission.   If the server (or administrative
domain to which the server belongs) is going to insist on use of
Message Submission (and authentication) for initial message
submission, then presumably the SMTP connection is going to be

If you connect via Port 587, what you are connecting to is,
formally at least, not an SMTP server but a Message Submission
(RFC 4409) server.

Frank's comments also apply here.

No lecture necessary, but I'm still having trouble figuring out
what changes need to be made to 2821bis, especially in the light
of the "...arrangements are private and fall outside the scope
of this specification..." text in 2821bis section 3.6 (I have
changed the sentence immediately before that one to be much less
tentative, since 4409 is a Draft Standard already).


--On Saturday, 31 March, 2007 16:09 -0400 "Robert A. Rosenberg"
<hal9001(_at_)panix(_dot_)com> wrote:

At 10:33 -0400 on 03/31/2007, John C Klensin wrote about
Submit and HELO (was: Re: RFC2821bis-01 Issue 3: EHLO param:


I think this is a Submit issue, rather than an SMTP one, so
don't know quite how to summarize it into an issues that is
2821bis-relevant.   If you disagree, please explain.


Yes I agree that it is mainly a Submit issue BUT since 2821bis
says that HELO is a valid way of initiating a SMTP Session
(although EHLO is the preferred/suggested method) we have a
conflict with Submit's requirement for
authentication/authorization and at least a note of this is
IMO useful in the HELO section (maybe just noting that HELO is
not compatible with Submit and pointing at the Submit RFC for

My logic on the existence of a conflict is as follows:

  1) To start a SMTP Session, I issue a HELO or EHLO.
  2) To connect to an SMTP Server via Port587 (ie: As a MSA
session as opposed to a MTA session - IOW: to inject new mail
not just pass along preexistent [in the system] mail) the
submitter must be authorized to use the Server.