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The IDLE disconnection timeout is hardwired in the Dovecot code

    http://wiki.dovecot.org/Timeouts

It's set to the RFC minimum of 30min.

I am ok if connection is closed automatically after 30 min if client is not responding but connection is not being closed even after 2 days.

Hmm. I can't think of why dovecot wouldn't time out. I think maybe the problem is with your webmail system -- it's not detecting when a client connection goes away and releasing all the resources associated with that user.

This is not a typical problem though -- most webmail software do not keep persistent IMAP connections open during a session unless they use some IMAP proxy.

Are your IMAP connections connected to the webmail server or an IMAP proxy, and is that connection active (despite webmail user disappearing)?

Joseph Tam <jtam.home@gmail.com>