<DKIM> Migrating from Cyrus to Exchange and from mbsync -> offlineimap in the process

[Nicolas Sebrecht]

On Tue, Jul 26, 2016 at 01:07:25AM +0200, Ævar Arnfjörð Bjarmason wrote:

> Moving to offlineimap worked right away. It's doing something
> different with the IMAP protocol that works with Exchange. Instead of
> hanging for a long time until the server seems to disconnect the
> connection it downloaded all the messages in very short order.

AFAICT, users have opposite experiences. It's hard to tell why mbsync
works better for some and offlineimap works better for others while in
similar environment.

>  * cons: Getting mail with offlineimap takes a lot longer, around 2
> minutes to just find out that it needs to do very little. Took around
> 10-20 seconds with mbsync, although this was on Cyrus, and I have
> around 700K messages in my INBOX. So it may be Exchange that's slower,
> I'm not sure.

Interesting. It's quite possible we have improvement ways in this area.

Frankly, I've downloaded mbsync some time ago. I could not understand
how it works during the free time I've had to allocate to this task.

If someone has hints or can describe how it works for discovering
changes and "trigger" the syncs, please let us know.

IMAP is not an easy protocol by design and implementation details in
both servers and clients lead to surprising results, sometimes.

Thank you much for this constructive feedback.

-- 
Nicolas Sebrecht