Issue with POP accounts getting locked.

Andreas Winkelmann ml at
Mon Jan 12 05:44:09 EST 2009

> I have been facing this issue for quite some time now.
> We have a shared hosting server and cyrus-imapd-2.3.7-4. The issue is as
> below.
> 1. Most of the time some of our roaming POP service users connect to the
> server via a Data card on their laptops. Due to the travel they receive
> varying bandwidth through their ISP and at times their email client
> disconnects the POP server without properly terminating the POP session.
> Thus leaving the stale lock on the pop server. We have to manually remove
> the lock every time such thing happens. (We also use a script to do this)
> 2. Issue occurs when there is access to the email POP account from
> multiple
> Email Client at the same time. The users face issue of POP lock.
> I assume this is protocol level issue faced by cyrus,  Can anyone tell me
> if
> there is any updated cyrus version /patch  where in we can eliminate the
> issue of
> 1. Stale lock getting ever created on the server.

There is an option poptimeout in imapd.conf you can modify it, but not
setting lower than 10 minutes without modifying the Sourcecode. This limit
is given from rfc.

   A POP3 server MAY have an inactivity autologout timer.  Such a timer
   MUST be of at least 10 minutes' duration.  The receipt of any command
   from the client during that interval should suffice to reset the
   autologout timer.  When the timer expires, the session does NOT enter
   the UPDATE state--the server should close the TCP connection without
   removing any messages or sending any response to the client.

Check if the ISP really closes the TCP/IP Connection or maybe it keeps it
open for a faster reconnect of the roaming Users.

> 2. Multiple email clients can login at the same time.

This is designed by Protocol. If a Client connects via POP3, the Mailbox
must be locked.

Maybe IMAP is an option?

> For issue 1.  is concerned as far as my experience goes cyrus faces the
> issue of stale locks more often than other POP servers.
> Does anyone has any remedy on this?


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