[Dovecot] Retrieving unread message count

[Timo Sirainen]

On 17.10.2010, at 23.49, Brandon Davidson wrote:

> Eventually I'd like to see it using RFC5819 LIST-EXTENDED, but that requires
> a fair bit of work. In the mean time I'm trying to speed up the existing
> iteration. I've got it working using 'STATUS "mailbox" (UNSEEN)', but the
> language in RFC3501 suggest that this may be slow. There is a
> counterproposal to use RFC4731 ESEARCH and do 'SELECT "MAILBOX"'; 'SEARCH
> RETURN (COUNT) UNSEEN'.

The reason why STATUS is mentioned to be possibly slow is to discourage clients from doing a STATUS to all mailboxes.

>> From an IMAP server perspective, which do you anticipate would be faster?
>> From a client perspective it seems like STATUS would be better since it
> involves less round-trips to the server and less output parsing, but given
> the warnings in the RFCs there is concern that it is in fact be more
> expensive.

STATUS is definitely faster than SELECT+SEARCH with all IMAP servers.