[Mailman-Users] Threading for integration with message board

Brad Knowles brad at stop.mail-abuse.org
Thu Oct 5 09:17:58 CEST 2006

At 6:41 PM -0500 10/4/06, Robert Hsiung wrote:

>  #1 could be addressed by embedding, as I described, the message
>  number in the original Reply-To: header, because then you could count
>  on it being included in the To: header of replies.

No, because the "Reply-to:" header has to contain an e-mail address 
and not a message number, so you can't go off and just change the 
format of that header without breaking every other mail program on 
the planet.

Moreover, when the mailing list is sending out the cooked version of 
the message, it has no idea what message number will have been 
assigned to that message by the archiving system.  It would know the 
value of the message-id header, but as we've said before, this 
doesn't always do us any good.

>  #4 seems like it would be easy to fix, since you know the posts
>  belong together and which came first.

That would require potentially re-parsing and modifying every single 
message in the archive, every time a new message comes into the list. 
The ramifications of having to go back and re-parse and modify a 
potentially never-ending string of previous messages in the list just 
because some new message came in on a thread three years after the 
previous message, is just ... mind boggling.

You can't properly fix #4 until the entire archive is implemented 
exclusively as a real database, and the display of the archive is 
always generated on-the-fly.  This is what mail and news clients 
effectively do when they use Jamie's algorithm, and this is what the 
archive server would also have to do.

In particular, this would mean that you could not pre-generate the 
cooked HTML version of an archive message, and message numbers in an 
archive could change whenever some new message comes into the archive 
in an earlier thread.  Not having persistent message numbers would 
break the ability to post links to specific archive messages on the 
list, because tomorrow there might be a different message with that 

You can resolve the latter issue by getting away from message numbers 
entirely and going with a scheme based on the originating message-id 
header, but you'd have to add some additional intelligence to handle 
the potential problem of message-id collisions, etc....

So, there's lots of work here that needs to be done to fix the 
archiving system, yes.

>  Is it possible to get Mailman to insert a variable "+detail" in the
>  Reply-To headers? If so, I could use my threading system and Mailman
>  both...

I'm sure you could write such a module, yes.

Brad Knowles, <brad at stop.mail-abuse.org>

"Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety."

     -- Benjamin Franklin (1706-1790), reply of the Pennsylvania
     Assembly to the Governor, November 11, 1755

  Founding Individual Sponsor of LOPSA.  See <http://www.lopsa.org/>.

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