Question regarding message-ids
We have a mm2 installation. A user is regular memeber on two lists:
- A mail goes to both lists.
- That mail is distributed via both lists.
- The mail is delivered twice (to an exchange server), in two SMTP sessions, to the same user adress. I get two positive delivery confirmations.
- since the message-id is identical, exchange is performing duplicate message elimination
Since the mails are in fact NOT identical (different Subject -- each lists adds their own [foo] and [bar] prefix), I'd very much prefer a new message-id for the distributed mails.
I'm sure I can hack something up in Postfix, but is there an easy way (tm)?
-- Ralf Hildebrandt Charité - Universitätsmedizin Berlin Geschäftsbereich IT | Abteilung Netz | Netzwerk-Administration Invalidenstraße 120/121 | D-10115 Berlin
Tel. +49 30 450 570 155 ralf.hildebrandt@charite.de https://www.charite.de
On 9/13/23 7:42 AM, Ralf Hildebrandt via Mailman-Users wrote:
- A mail goes to both lists.
A singular email is sent to both lists as a recipient.
- The mail is delivered twice (to an exchange server), in two SMTP sessions, to the same user adress. I get two positive delivery confirmations.
This is what I would expect.
- since the message-id is identical, exchange is performing duplicate message elimination
Okay.
Since the mails are in fact NOT identical (different Subject -- each lists adds their own [foo] and [bar] prefix), I'd very much prefer a new message-id for the distributed mails.
Oh ... that's not where I thought this was going to end up.
I'd have to go back and read RFCs on what the underlying purpose of the Message-ID is and if using it's definition the messages are identical or if they should have different Message-IDs after leaving the mailing list.
I can see it both ways. The message is the same and not the same at the same time.
I'm sure I can hack something up in Postfix, but is there an easy way (tm)?
I'm sure there are things that can be done too. My concern becomes what happens to threading when messing with the Message-ID? Conditionally messing with the Message-ID is an entirely different problem.
This will probably be an interesting thread to read.
-- Grant. . . . unix || die
- Grant Taylor via Mailman-Users <mailman-users@python.org>:
- The mail is delivered twice (to an exchange server), in two SMTP sessions, to the same user adress. I get two positive delivery confirmations.
This is what I would expect.
I just wnated to make this clear :)
- since the message-id is identical, exchange is performing duplicate message elimination
Okay.
Since the mails are in fact NOT identical (different Subject -- each lists adds their own [foo] and [bar] prefix), I'd very much prefer a new message-id for the distributed mails.
Oh ... that's not where I thought this was going to end up.
Neither did I.
I'd have to go back and read RFCs on what the underlying purpose of the Message-ID is and if using it's definition the messages are identical or if they should have different Message-IDs after leaving the mailing list.
I can see it both ways. The message is the same and not the same at the same time.
Yes, I agreee. That's why I wanted to discuss this. This could easily be solved by MM moving the Message-Id: to Resent-Message-Id: (and Postfix would the - if propery configured - add a new Message-Id
I'm sure I can hack something up in Postfix, but is there an easy way (tm)?
I'm sure there are things that can be done too. My concern becomes what happens to threading when messing with the Message-ID? Conditionally messing with the Message-ID is an entirely different problem.
This will probably be an interesting thread to read.
:)
-- Ralf Hildebrandt Charité - Universitätsmedizin Berlin Geschäftsbereich IT | Abteilung Netz | Netzwerk-Administration Invalidenstraße 120/121 | D-10115 Berlin
Tel. +49 30 450 570 155 ralf.hildebrandt@charite.de https://www.charite.de
On 9/13/23 5:42 AM, Ralf Hildebrandt via Mailman-Users wrote:
We have a mm2 installation. A user is regular memeber on two lists:
- A mail goes to both lists.
- That mail is distributed via both lists.
- The mail is delivered twice (to an exchange server), in two SMTP sessions, to the same user adress. I get two positive delivery confirmations.
- since the message-id is identical, exchange is performing duplicate message elimination
Since the mails are in fact NOT identical (different Subject -- each lists adds their own [foo] and [bar] prefix), I'd very much prefer a new message-id for the distributed mails.
I'm sure I can hack something up in Postfix, but is there an easy way (tm)?
Change the message-id as they pass through Mailman and you break threading. Some people may get a direct copy of the message (instead of, or in addition to the copy from the list). That will then have a different Message-ID to what people who just gets the message from the list, and thus the Reference: and In-Reply-To: headers won't match.
Note, same Message-ID NEVER meant "Identical" messages, it meant from the same original message. Mail Transport Agents that just forward a message with only "Administrative" changes, should not change the Message-ID.
-- Richard Damon
Ralf Hildebrandt via Mailman-Users writes:
I'm sure I can hack something up in Postfix, but is there an easy way (tm)?
Get rid of Exchange. :-)
This is not something Mailman should implement in my opinion. The author decided to send a single message to multiple addresses. Evidently that author considers it to be the same message regardless of which list delivers it. I also don't think it makes for a healthy community based on the points below. It may work fine in some special cases, but it seems likely to cause a lot of confusion.
Now, as Richard Damon points out, whether two messages should have the same Message-ID is not a matter of identical content, it's whether users consider them "the same". Since a mailing list is an intermediary, that is, it removes a message from the Internet mail system, processes it, and then reinjects it, the mailing list can claim to be the originator of the distributed post in some sense (though obviously not in the sense of copyright law!) So if you want to make this decision for all subscribers, you can do that.
However, here are some points to consider.
- Are the recipients who subscribe to both lists unanimous in their desire to duplicate messages in this way? If not, are the individuals who want distinct messages "more important"?
- Unless you are very clear about this change, some recipients may think the authors are sending multiple copies, and ask them to desist.
- Anybody who uses reply-all will also have their posts duplicated in the same way. This will create a weird proliferation of threads, which I doubt will display sanely in most mail clients.
- It will very likely cause more than usual redundant posts because even people who are subscribed to both will be missing most of the potentially relevant replies.
participants (4)
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Grant Taylor -
Ralf Hildebrandt -
Richard Damon -
Stephen J. Turnbull