[Imap-protocol] QRESYNC and new arrivals which get deleted
immediately through VANISHED
alexey.melnikov at isode.com
Tue Jul 17 10:55:35 PDT 2012
On 17/07/2012 18:11, Jan Kundrát wrote:
> On 06/08/12 18:02, Jan Kundrát wrote:
>> Finally, my last question is why does QRESYNC require me to issue an
>> ENABLE QRESYNC at all? I feel like the SELECT ... QRESYNC should be
>> enough to tell the server that I'm really expecting the VANISHED
> I think I have found an answer to this -- if the client doesn't have
> any cached state for a particular mailbox, it cannot really SELECT
> QRESYNC that.
> If it tried to use a HIGHESTMODSEQ = 1, it would risk an enormous
> amount of data being transferred in VANISHED EARLIER as the server
> would have to inform about each and every expunge which has happened
> in the mailbox since its creation. This is due to the known-uids ABNF
> item format which doesn't provide any way of sending "nope, I don't
> know about any UIDs" -- the list can either be missing, or contain at
> least one item.
> If I understand everything correctly, ENABLE QRESYNC is therefore
> still required as long as one wants to receive VANISHED instead of
> My apologies for assuming that it's useless :).
> Also is probably means that a QRESYNC-capable clients have to use
> SELECT ... CONDSTORE when they open a mailbox for the first time.
This can be an option.
> I'd appreciate if someone could verify these assumptions -- they look
> plausible to me, but I didn't see any flaw in my previous reasoning,
> either :).
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