Message threading - perspective....
Many people including myself have asked in various ways for message threading, or sorting by subject or sender.
I thought i would look at what was involved.
There may be better sources, but this article
http://people.dsv.su.se/~jpalme/ietf/message-threading.htmlis quite readable, but makes clear it may not be a straightforward matter, at least in 1998 that was the case.
Perhaps things have changed, but what i take from this is that it is not always a simple matter of chaining together message ids and "in reply to" s, as some clients put less useful info in these fields.
So whilst still urging kostya to bump this up the list, i recognise it is a non trivial extension.
I also wonder what is the implication of trying to display as a thread a conversation extending over time, such that the most recent message is loaded, some more message headers are loaded, and some messages are just on the imap server. A strategy for loading at least all the headers needs to exist.
My prediction is that this feature should come eventually, but i think we must be patient and understand the complexities. Thunderbird did not initially offer threaded view, supporting my inference that it is non trivial.
BTW, I would settle for threaded view using the message ids and in reply tos, but dont want the client to use message subject lines to guess at threads by matching them.
The latter can produce perverse results, and to work it has to consider not just subject, but subject, date, sender, recipient together. A sort of fuzzy logic problem!
Instead i would ask for a second function, the ability to SORT by subject, sender, or recipient, the equivalent of clicking in the column header in thunderbird. This is not threading or conversation mode, it is sorting (but again, there are implications for traffic between client and server ).