[Mailman-Developers] in-reply-to problem

[Stephen J. Turnbull]

>>>>> "Brad" == Brad Knowles <brad at stop.mail-abuse.org> writes:

    Brad> 	You could spend a trillion dollars on this problem and
    Brad> not find a solution.  The entire computer industry has been
    Brad> working on AI since the early 1960s, and they haven't solve
    Brad> it yet, and don't appear to be much closer today than they
    Brad> were back then.

That's a bit pessimistic, don't you think?  What can be done without
I-R-T or References doesn't require AI.  Plenty of MUAs solve the
problem of threading messages with no I-R-T header satisfactorily (ie,
messages that are in the same thread almost always appear within a few
lines of each other in the summary).

K.S., the problem here is that threading algorithms require data about
the other messages in the thread.  Mailman handles messages _one at a
time_, and does not have the information about other messages
(specifically dates and subjects) needed to guess at threading.  So
forget about hacking Mailman; you'd kill performance, most likely.

On the other hand, an archiver (such as Pipermail, distributed with
Mailman, or MHonArc, a popular third-party archiver) does (typically)
have that information, at least in "rebuild-the-whole-shebang" mode,
and I would say that you should look at archivers, not at Mailman
proper.  Also look in the mailman FAQ for how to use a 3rd-party
archiver with Mailman; you can probably find one that does a better
job than Pipermail does.  MHonArc would be a good bet.

http://www.jwz.org/doc/threading.html describes a threading algorithm
that is fairly robust to this problem in my limited experience with it

That's as far as I'm willing to go though.  Really, you should get
your users to switch to an MUA that can handle headers that were
standardized in 1975 or so.  And there are plenty of MUAs that can do
something sane about pseudo-threading messages without I-R-T.

-- 
Institute of Policy and Planning Sciences     http://turnbull.sk.tsukuba.ac.jp
University of Tsukuba                    Tennodai 1-1-1 Tsukuba 305-8573 JAPAN
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