[Mailman-Developers] RFC 2822 complicance (was Re: 2.0.x qrunner bug (bad one))

[Norbert Bollow]

Jason R. Mastaler <jason-list-mailman-developers@mastaler.com> wrote:

> barry@zope.com (Barry A. Warsaw) writes:
> 
> > The only argument I'd make is that the standards are really geared
> > toward cooperation of alien systems, i.e. two unrelated processes
> > that need to exchange mail messages.  In Mailman's case, an argument
> > can be made that it and its MTA are working in tandem to perform a
> > function.
> 
> That would be a practical and reasonable argument.

Yes.  This means that if you're maintaining both the MTA and a
MLM (mailing list manager) program which gives messages to it,
then you can set things up so that the MLM expects the MTA to
munge the messages in some ways that are not specified in the
RFCs.

However, given that the GNU Mailman project maintains only an
MLM and no MTA, and this MLM communicates with the MTA through
an interface that is specified in an internet standard, there
is IMO no doubt that it's Mailman's responsibility to comply
with this standard.

Barry A. Warsaw <barry@zope.com> wrote:

> >>>>> "JRM" == Jason R Mastaler
> >>>>> <jason-list-mailman-developers@mastaler.com> writes:
> 
>     JRM> Then shouldn't you also have Mailman add a Message-ID header
>     JRM> as well?  SMTP on qmail doesn't add that either.
> 
> I thought about the same thing, and /almost/ added it, but then I
> checked RFC 2822.  While it requires one Date: header, Message-ID: is
> actually /not/ required, although it "SHOULD be present".  I took that
> as license to be as conservative as possible. :)

The term "SHOULD" has a well-defined meaning in RFCs... RFC2822
explicitly invokes RFC2119, where this, and related terms are
defined as follows:

  1. MUST   This word, or the terms "REQUIRED" or "SHALL", mean that the
     definition is an absolute requirement of the specification.

  2. MUST NOT   This phrase, or the phrase "SHALL NOT", mean that the
     definition is an absolute prohibition of the specification.

  3. SHOULD   This word, or the adjective "RECOMMENDED", mean that there
     may exist valid reasons in particular circumstances to ignore a
     particular item, but the full implications must be understood and
     carefully weighed before choosing a different course.

  [..]

With other words, given that the Message-ID: header is a SHOULD,
if you want to choose a diffferent course, you (as maintainer of
Mailman) have a responsibility to understand and carefully
consider the full implications of not adding a Message-ID:
header to messages that are _originated_ by Mailman.

There are several such implications, in areas like automated
filtering of duplicate messages, debugging mail problems (some
MTAs log the contents of the Message-ID: header), and spam
filters (I know of at least one ISP where all messages without
Message-ID: are considered to be probably spam).

I think it's probably much less work to just add the header than
to "understand" and "carefully weigh" all these implications.

Greetings, Norbert.

-- 
A founder of the http://DotGNU.org project and Steering Committee member
Norbert Bollow, Weidlistr.18, CH-8624 Gruet   (near Zurich, Switzerland)
Tel +41 1 972 20 59       Fax +41 1 972 20 69      http://thinkcoach.com
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