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

[Robert Schetterer]

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