[ILUG] extremely slow pop3, but imap is fine

[Kae Verens]

Justin Mason wrote:
> On Fri, Mar 27, 2009 at 10:03, Justin Mason <jm at jmason.org> wrote:
>>> any ideas why it would mostly affect POP3? appears to be slowing our other
>>> services, but POP3 is the most serious.
>> this looks to me like the kernel buffers are filling up, returning the
>> EAGAIN ("try again later" basically) to the app level.  have you
>> considered it may be a broken QoS policy or similar on the router
>> deprioritising POP3 traffic?
> 
> hmm. also, when small packets get through fine but large packets
> have trouble, that smells like MTU issues.

problem solved.

a new router had been installed in the datacentre, but some eejit had set a cap of 4Mb on it, so it was simply a 
bandwidth problem.

kae