[Dovecot] POP3 locking

[Ken A]

Timo Sirainen wrote:
> On Jul 31, 2008, at 8:10 PM, Mark Sapiro wrote:
> 
>> On Wed, Jul 30, 2008 at 06:05:27PM +0200, Kai Schaetzl wrote:
>>>
>>> but it seems to be off by default. From my dovecot.conf (1.07):
>>>
>>> #pop3_lock_session = no
>>>
>>> I think it should be on by default.
>>
>>
>> The problem is if you have an MUA/MDA retrieving lots of messages
>> over a potentially slow connection, the mailbox can remain locked
>> for a very long time for a read-only operation.
> 
> Or before when dialups were more common, if the modem disconnected you'd 
> have to wait several minutes until the previous connection timed out.

Still very common in rural USA. We see occasional pop3 locks that last 
hours while someone on a 26.4Kbps connect downloads mail. rfc1939 says 
it should be locked. I do understand why it's not default in dovecot 
though, since Dovecot is primarily an IMAP server, and the idea of 
locking a mailbox for hours is probably a bit repulsive to the 
developer. :-)

Ken

> 
>> The problem that requires doing it is basically a client problem.
>> Namely, some clients may get confused if in the middle of a series
>> of RETR commands, they get a mailbox locked reply.
> 
> This should never happen with Dovecot. But what could happen is that the 
> message got expunged and the RETR would fail because of that.
> 


-- 
Ken Anderson
Pacific.Net