Mailbox is locked by POP server

Martin Schiøtz malinux at
Tue Dec 19 21:21:40 EST 2006

On 12/19/06, Pascal Gienger <Pascal.Gienger at> wrote:
> former03 | Baltasar Cevc <baltasar.cevc at> wrote:
> > Hi Martin,
> >
> > Personally I do not use POP3 any more - however I remember that there
> > was a limitaition of 1 connection per mailbox in other servers.
> Yes.
> The POP3 RFC states that operations such as DELEte a message will become
> "final" after issuing a "QUIT" command. If connection breaks, no change is
> made to the mailbox.
> For having multiple concurrent POP3 access to a mailbox a complete
> transaction based model including rollbacks would be needed to implement
> proper POP3. I don't think anybody wants to improve pop3d to accomplish
> that ;-)

Personally I use IMAP and Thunderbird, but a lot of the users on this
postfix/cyrus server use POP and Outlook. It looks like the problem
occurs with Outlook clients using POP. At least I have seen the
problem with Outlook 2002.
I'm don't think that it has to do with loss of internet connectivity
since the server is on the same switch as some of the Outlook users
and I have never seen this problem using Thunderbird.
I have seen the problem occur when Outlook automatically is doing
'send/recieve' (with Outlook 2002 the default is every 2 minutes) and
when the user is keeping Outlook open for a longer time. I can see
from the log that only this client tries to access POP3???

I will try to get a dump to see if Outlook is sending a QUIT command....

- Martin

More information about the Info-cyrus mailing list