Re: sluggish IMAP updating?

[Simon Josefsson <simon@josefsson.org>]

Greg Troxel <gdt@work.lexort.com> writes:

> Simon Josefsson <simon@josefsson.org> writes:
>
>> Greg Troxel <gdt@work.lexort.com> writes:
>>
>>> [gnus/dovecot doesn't notice new messages right away]
>>
>> Does toggling nnimap-need-unselect-to-notice-new-mail help?
>
> Yes, that seems to fix the problem.   From *imap-log*, I can see that
> STATUS was returning no new messages, but after UNSELECT, it gives the
> right status.

Right.

>> Does toggling nnimap-need-unselect-to-notice-new-mail help?
>
> The word from dovecot is that STATUS on a selected mailbox is SHOULD NOT
> to start with, and MUST NOT to check for new mail.  See 6.3.10 of
> RFC3501.
>
> http://dovecot.org/pipermail/dovecot/2007-May/023045.html
>
> Plus, doing lots of STATUS commands seems to be disfavored but I don't
> understand IMAP well enough to understand.

nnimap was written when RFC 2060 was current, and we haven't really
updated it for RFC 3501.  I suspect the notes in 6.3.10 was added as a
result of nnimap and other implementations behaviour, but the problem is
that I don't know of a good way to implement this in Gnus without using
STATUS (and, alas, I wouldn't have time to implement anything even if I
had some ideas).  Note that I cannot see that RFC 3501 allows servers to
respond with incorrect data in this situation, which dovecot appears to
be doing.

> Given this, I think it makes sense to set
> nnimap-need-unselect-to-notice-new-mail to t by default.

This will slow things down for other users...  Are you using the latest
Dovecot version?  Maybe we can improve the manual.

I don't have a strong opinion on what the default should be.  If others
think it is safer to let it be t by default, by all means change it.

/Simon