On 30/03/12 21:59, John Rouillard wrote:
> 
> John Rouillard <rouilj@users.sourceforge.net> added the comment:
> 
> In message
> <1333106220.03.0.265807397089.issue2550752@psf.upfronthosting.co.za> ,
> Tom de Vries writes:
> 
>> New submission from Tom de Vries <tom@codesourcery.com>:
>> we're using roundup as issue tracker and exchange as email server.
>>
>> We have a problem related to an issue with both:
>> - me and,
>> - a mailing list I'm a member of in the nosy list.
>>
>> When I do an update of the issue, emails get send to me and the mailing
>> list (due to configuration option NOSY_EMAIL_SENDING == single), with
>> each email containing only a single addressee.
>>
>> when the 2 messages arrive, one stays in my inbox, the other one is
>> filtered to the mailing list folder.
>>
>> The problem is that sometimes only one message arrives (any of the two).
>> I've tracked this down to the following:
>> when a message arrives at the exchange server, and that message has the
>> same Message-id and the same Date field as an earlier message, the
>> second message is dropped (documented here:
>>
http://technet.microsoft.com/en-us/library/dd577073%28v=exchg.80%29.aspx#1
>> ).
>>
>> When roundup sends the 2 emails, it sends it with the same message-id,
>> but not necessarily with the same Date.
>>
>> So if the Date field is different, I receive 2 emails. If the Date field
>> is the same I receive 1 email (the first one to arrive).
>>
>>From my user perspective, this is bad: I expect the email addressed to
>> me to appear in my inbox.
>>
>> [...]
>> If we force the Date to be the same for all messages, I'll never get two
>> messages, only one (timing-dependent which one).
>>
>> If we force the Date to be different for all messages, I always get two
>> messages, but it's a not so pretty workaround for the specifics of
>> exchange duplicate message detection, and may not work for other similar
>> duplicate elimination programs.
> 
> True, but I think changing the message-id will be more difficult. It
> should definatly be an option regardless of which solution is adopted.
> 
> It's really stupid that exchange can't turn that off. I have had
> duplicate detection in my email chain for a couple of decades, and
> it's only considered a duplicate if it's the same message (messageid)
> handled the same way (i.e. is delivered to the same mailbox/folder).
> 
>> I think the cleanest fix would be to have a different message-id for
>> each message. But, I'm not sure about the drawbacks of doing that.
> 
> Well one of the issues is that clients use the In-Reply-To: <msgid>
> header for threading in a client.
> 
> The comment in:
> 
>    ./roundup-1.4.19/roundup/mailgw.py:
>         # try in-reply-to to match the message if there's no nodeid
> 
> indicates that it does compare the in-reply-to (whose value is the
> message id of the message being responded to) and expects a message id
> matching what it sent. I am not sure if there is support for a many->1
> message-id -> actual message mapping which would be needed if a
> message resulted in multiple message-id's.
> 

Hi,

Ah, thanks for pointing that out, I never noticed roundup does threading
of messages.

I've considered the following options to still make the threading work:
- Use the 'References:' field to pass the original message-id. Could be a
  solution, but I'm not sure if all mail clients will pass that on reply.
- Use an x-header such as x-round-message-id, but my own mail client 
  doesn't pass x-headers. And it wouldn't work for threading on the
  mail client, only roundup would recognize this field.
- add a serial number (unique for each nosy list member) to the message-id
  when sending mail, and remove it when receiving mail. Works for threading
  in mail client and in roundup, but doesn't thread messages when one
  person on the nosy list replies with cc to another person in the nosy
list.

Any preferences or better ideas, anyone?

Given that changing the message-id will most likely will break threading in 
one way or another, the option of forcing the Date to be different to work 
around the specifics of the exchange duplicate message detection starts to
sound less awkward.

>> What I understand from the standard (http://tools.ietf.org/html/rfc5322)
>> though is that same or different message-id depends on the intent of the
>> sender:
>> ...
>> In all cases, it is the meaning that the sender of the message wishes to
>> convey (i.e., whether this is the same message or a different message)
>> that determines whether or not the "Message-ID:" field changes, not any
>> particular syntactic difference that appears (or does not appear) in the
>> message.
>> ...
>> One could argue that the 2 emails messages are different because each
>> has a different addressee.
> 
> Well I would claim the message is a response to a single event:
> 
>   the roundup update
> 
> It really is a single message going to multiple people.  Roundup is
> just changing the envelope addressing and not really the message.

I think one can argue one way or the other on whether these 2 messages
are the
same or not.
But to respond to your argumentation, the difference in the 2 messages
is not
limited to the envelope. The addressees inside the envelope are also
different,
which is why my feeling is that they're different.
If the addressees inside the envelope were the same, I would have the
guarantee
to receive a message with me as TO or CC, and my filters would keep it
in my inbox,
and the biggest part of my problem would be fixed.

Thanks,
- Tom

> 
> ----------
> nosy: +rouilj
> 
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> <http://issues.roundup-tracker.org/issue2550752>
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