Timo Sirainen <t...@iki.fi> writes:
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.
It's a shot in the dark, but I had a problem with a different client,
where semi-large attachments was problematic.
It turned out to be a TCP scaling problem. If a router/firewall drops
packets with a TCP scaling option set, the endpoints disagree on how many
outstanding non-ACK packets are allowed, resulting in timeouts.
http://support.microsoft.com/kb/935400
http://en.wikipedia.org/wiki/TCP_window_scale_option
The Microsoft KB does hint those versions of Outlook may be affected, but
I can't figure out why there would be a difference between Dovecot 2.1
and 2.2.
Joseph Tam <jtam.h...@gmail.com>
