[Mailman-Users] Getting duplicates when people CC list

[John W. Baxter]

On 5/1/06 7:47 AM, "John W. Baxter" <jwblist at loricamail.com> wrote:

> On 4/30/06 1:28 AM, "Tony G" <4ylyh9g02 at sneakemail.com> wrote:
> 
>> It seems I am getting duplicate messages from mailman v2.1.5 when senders
>> send
>> both TO and CC to the list. For some reason no one else in the list is
>> acknowledging this issue so I look like an idiot complaining about it, but
>> I'm
>> seeing several instances of it per day.
>> 
> 
> I'm seeing duplicates too, reading in Microsoft Entourage (which differs
> greatly from Outlook).  I haven't taken the time to analyze them (delete
> works fine).  Since some of them are in threads crossposted to users and
> developers lists, I see four copies of those.
> 
> Two copies of a message with this Message-Id:
> Message-Id: <1146489146.11009.13.camel at geddy.wooz.org>
> Message-Id: <1146489146.11009.13.camel at geddy.wooz.org>
> reached me through the developers list (based on the List-xx headers)
> 
> This is the one in which Barry started out
> "I agree that we need a lot more data"
> 
> And two more copies came via the users list.

Tony, I think you need to review your Outlook rules.

My duplications are produced in our mail server's mail sorting process, and
the key is the presence of prefixes for both -users and -developers in the
Subject: lines of the problem messages.

Considering only the two copies from the Developers list, the divergence
appears to be in our mail processing.  The messages arrived our our
world-facing machine with the same Exim Id:

Received: from smtp-vbr8.xs4all.nl ([194.109.24.28]:3979)
    by entiat.olympus.net with esmtp (Exim 4.42)
    id 1FaYCW-0006pK-O1
    for jwblist at loricamail.com; Mon, 01 May 2006 06:12:33 -0700

and 

Received: from smtp-vbr8.xs4all.nl ([194.109.24.28]:3979)
    by entiat.olympus.net with esmtp (Exim 4.42)
    id 1FaYCW-0006pK-O1
    for jwblist at loricamail.com; Mon, 01 May 2006 06:12:33 -0700

(ie, the same).

And having looked at the server logs, I now know what is happening in my
case.  I have our mail processing sort list mail into IMAP folders based
on--in the case of these lists--the presence of the subject prefix, and
these messages have prefixes for both lists in the Subject: header.

So my copy for -users gets sorted into my folders for -users and for
-developers, and my copy for -developers gets sorted into -users and into
-developers.

Note:  the next revision of our mail processing will allow sorting based on
arbitrary headers--the List- headers for example.