Hi folks, there's an extension [1] to IMAP specifying the THREAD command to return list of message sequence numbers grouped to indicate the threading of them. That draft currently defines two algorithms, one of them based solely on Subjects (which is rather dumb) and the second one, combining Subjects with In-Reply-To (etc) headers.
The second method is actually advertised and supported by Dovecot. However, I've got quite a lot of friends that lack the knowledge of what the "Subject" field is for, so they just leave it empty. The problem comes when I want Dovecot to return the threads - it follows the ietf draft, so it doesn't check only for references from message headers, but also the subjects. The result is that especially those mails with empty subjects are incorrectly grouped together.
So, I'd like to see a feature that would eliminate this problem. It seems to me that there are currently two methods:
a) Don't look at the Subject field at all - altough it might increase the speead a bit, it has some disadvantages as well, namely that you'll lose threading if someone uses broken mail client (but broken only in such a way that it preserves subjects)
b) Ignore the Subject field if it is empty (after stripping stuff like "re:" etc - just as that draft specifies). Seems reasonable, IMHO.
Of course we can't modify the result of a THREAD command (that would break the standard and it generally isn't a proper way to go), so we'd have to introduce another one.
I'm pretty sure that especially method a) is very simple (and even simpler if I decided to break the standard by "fixing" the THREAD command), but I really don't like <rant>portable assembler :)</rant> <politely>C</politely>, so are there any chances for this "new and fixed" command to be included into Dovecot? I mean, I might do that in a flawed and ugly way just for me and post a patch so that possible interested persons can pick it, or I migth persuade someone to do it, actually :). Do you think that it's worth the issue?
Does anyone have any experiences with talking to the IETF about possible extension of their draft?
Ideas?
[1] http://www.ietf.org/internet-drafts/draft-ietf-imapext-sort-17.txt
Cheers, -jkt
-- cd /local/pub && more beer > /dev/mouth