[Dovecot] Outlook 2010 very slow when using IMAP - are there any tweaks?

[Kaya Saman]

On Tue, Jul 3, 2012 at 12:36 PM, Robert Schetterer
<robert at schetterer.org> wrote:
> Am 03.07.2012 13:32, schrieb Kaya Saman:
>> On Tue, Jul 3, 2012 at 11:51 AM, Kaya Saman <kayasaman at gmail.com> wrote:
>>> On Tue, Jul 3, 2012 at 11:37 AM, Charles Marcus
>>> <CMarcus at media-brokers.com> wrote:
>>>> On 2012-07-03 3:12 AM, Kaya Saman <kayasaman at gmail.com> wrote:
>>>>>
>>>>> However this is a clean server with plenty of space left on the pool
>>>>> allocated for mail and it's additionally using ZFS too.
>>>>
>>>>
>>>> What OS? ZFS implementation/version? How is mail stored (maildir? mbox?)
>>>>
>>>> While I don't think this is your problem, just fyi, my understanding is that
>>>> it is fairly easy to implement ZFS wrong (which would cause serious
>>>> performance problems), and that the only decent ZFS implementation is Suns
>>>> (ie, what ships with Nexenta), or the latest FreeBSDs...
>>>>
>>>> Also, my understanding is that ZFS isn't the snappiest of filesystems even
>>>> when properly configured (you trade performance for data integrity).
>>>>
>>>> Personally, I'd recommend trying this on a traditional FS (XFS or Reiserfs
>>>> for maildir) and see if that changes things.
>>>
>>> FreeBSD 8.2 x64 using Maildir. ZFS is perfect no worries with that!!!
>>> Additionally the system is on a VMware cluster which is also fine -
>>> have checked all as diagnostics.
>>>
>>> The usage here is minimal, and since I also use ZFS at home too with
>>> quite a larger file system then at work (I know I know) and really
>>> hammer the heck out of it there is no issue.
>>>
>>>>
>>>>
>>>> On 2012-07-03 3:12 AM, Kaya Saman <kayasaman at gmail.com> wrote:
>>>>> The point is that I am monitoring using nload as well as other things
>>>>> and the maximum bandwidth being got with Outlook is a few Mbps burst,
>>>>> average 50kbps; while with T-Bird I get way over 130Mbps?
>>>>
>>>> Congrats - there's your problem... now you need to find out *why* this is so
>>>> slow... most likely a tcp dump analysis of a session is the only way - I
>>>> think there are people here who could help you analyze one (but not me,
>>>> sorry)...
>>>>
>>>
>>> Yeah, it seems to be M$ implementation of IMAP. I don't think that
>>> there's anything anyone can do.... Outlook seems to wait after each
>>> transmission (found using Wireshark).
>>>
>>>>
>>>> On 2012-07-03 3:41 AM, Kaya Saman <kayasaman at gmail.com> wrote:
>>>>> The PST's seem to be stored on local hard disk too.
>>>>
>>>> 'Seem' to be? You need to make sure, because if they aren't that could
>>>> definitely cause, or at least contribute to this kind of problem.
>>>>
>>>
>>> It is definitely stored locally!
>>>
>>>> --
>>>>
>>>> Best regards,
>>>>
>>>> Charles
>>>
>>> Regards,
>>>
>>>
>>> Kaya
>>
>>
>> Ok now probably related to this is that some folders are not able to copy??
>>
>> While dragging one folder from Outlook PST to the Dovecot IMAP server
>> in Outlook 2010, the transfer keeps bombing out?
>>
>> In the logs all I see are:
>>
>> : Error: stat(/mail/AD_Mail//
>>
>> errors.
>>
>> My user was actually testing by copying the Inbox with many
>> subdirectories into the INBOX on dovecot.
>
> check pst file is local , check if copy from local over imap with subdir
> in general
> possible with outlook
> check no virus scanner proxies are involved
>
>>
>>
>> Is this another Outlook related quirk or is it something serverside
>> which I need to change?
>>
>>
>> Regards,
>>
>>
>> Kaya
>>
>
>
> --
> Best Regards
> MfG Robert Schetterer
>
>

I attempted this myself as a check or test and Outlook claimed "Unable
to open Deleted Items"?

PST is local, subdirs are supported, no virus scanner or proxy in the way.

Regards,

Kaya