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

[Kaya Saman]

On Tue, Jul 3, 2012 at 12:47 PM, Kaya Saman <kayasaman at gmail.com> wrote:
> 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

Quick update:

when transfering from Dovecot to Dovecot via Outlook I got a message
popping up saying:

"The move operation cannot be completed. It is possible that the
destination server is unavailable or does not support subfolders"


I think this is the standard error being seen....

Regards,

Kaya