OT - EMEW (Enhanced Message-ID as Email Watermark) breaks pipermail threading

[Mark Sapiro]

I notice a few frequent posters on this list, including Jules since
late May, appear to receive list posts with Message-IDs munged with
EMEW watermarks. Thus their replies to list posts have In-Reply-To:
with the munged Message-ID which breaks threading in the pipermail
archive at <http://lists.mailscanner.info/pipermail/mailscanner/>
(every time Jules replies to a post, a new thread is started).

I am a Mailman developer and am concerned about what, if anything, I
should do about this for the near term. My specific concerns are

1. how wide spread is the use of EMEW likely to become.

2. How do I recognize the added data in the Message-Id? It looks like
the regexp 'EMEW-[0-9A-Za-z]{6}[0-9a-f]{32}-' will work and removing
the match will restore the original Message-ID (or at least the
immediately prior Message-ID). Is that a good regexp, or is there a
better one?

3. Are there products other than BarricadeMX that are munging
Message-IDs in other ways for similar reasons.

I haven't been able to find much on the web about this. I would
appreciate any advice or additional information anyone can point me to.

-- 
Mark Sapiro <mark at msapiro.net>        The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan