[Dovecot] pop3_lock_session question

[Rob Mangiafico]

On Wed, 4 Feb 2009, Timo Sirainen wrote:
> On Wed, 2009-02-04 at 11:17 -0700, Mark Costlow wrote:
>> Hello, I'm preparing to convert from qpopper + UW-IMAP to dovecot.
>> So far testing has gone very well.  One problem we haven't figured
>> out is that long-running POP sessions keep the mailbox locked, so that
>> the MDA times out while trying to deliver.  We're using "maildrop" as
>> our MDA if that matters.
> ..
>> We though this setting would address the issue:
>>
>>   # Keep the mailbox locked for the entire POP3 session.
>>   pop3_lock_session = no
>>
>> But it doesn't seem to.
>>
>> Any ideas?
>
> Switch to Maildir and the problem goes away. The issue is that the mbox
> file is read-locked when the first message is read. And since the POP3
> client most likely just keeps reading messages for the entire session,
> the mbox file kept read-locked all the time. Can't really be fixed
> without some larger redesign (which is really not worth it).

We see this as well with mbox and pop3 accesses where some pop3 clients do 
not logout (iphone's are the worst offenders) for 30-90 minutes it seems. 
Timeout settings in dovecot.conf do not seem to help. procmail backs up 
waiting to get access to the inbox to deliver mail.

Is there a global timeout we can set that will close any pop3 connection 
after say 15 minutes? Maildir is not an option currently for many of our 
servers that use openwebmail, which does not support maildir currently.

Not sure if these pop3 sessions are in a loop, just keeping the conenction 
open for a reason, etc... but they do not seem to do anything after the 
initial check besides not logging out...

Rob