[Dovecot] Outlook 2007 & 2010 hangs in v2.2?

Timo Sirainen tss at iki.fi
Thu Jun 5 17:40:31 UTC 2014

On 5.6.2014, at 20.23, Robert Schetterer <rs at sys4.de> wrote:

> Am 05.06.2014 17:02, schrieb Timo Sirainen:
>> On 5.6.2014, at 17.41, Martin Rabl <martin.rabl at rablnet.de> wrote:
>>> Am 05.06.2014 16:38, schrieb Timo Sirainen:
>>>> Has anybody noticed Outlook 2007 & 2010 (but apparently not 2013) hanging IMAP connections with Dovecot v2.2 (but not v2.1) when they're FETCHing large mails? I can't think of any reasonable explanation for this.
>>> how large?
>> I don't know yet if the mail size is even relevant. At least one hang was caused by downloading ~55 MB mail where it stopped just before the last 400 kB.
>> I find it strange that v2.2 has been out for a long time and nobody before this complained about any hangs.
> 55 MB mail may are rare ,i can test it ,but it will need some time ( old
> outlook install on clean new windows system....)
> perhaps anyone has an existing setup which could do it faster

Happens also with smaller mails, for example 3 MB and I think there were also even smaller ones like 1 MB. I see that once Outlook tried to download the same 3 MB mail 3 times and it stopped reading it when it had 400 kB left, but the 4th time succeeded. Dovecot sent exactly the same data with the same TCP packet boundaries all times (at least to Dovecot proxy - would have to look with tcpdump further to see if proxy does something differently..)

Anyway, nobody in general has had trouble with Dovecot v2.2 and Outlook 2007/2010? Maybe the problem is something else, although strange if it started happening only immediately after Dovecot upgrade.

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