Hi! I am still having the problem, isn't there anyone who has a hint for me? I changed the io scheduler from cfq to deadline, raised file descriptor limit to 300000 and still have no betterment. :( I installed the nagios check on the mail server itself to exclude network problems and checked the imap service on both interfaces (localhost and on the external ip). I also did this in parallel and noticed that when a timeout happens on one interface it is not constraining a timeout on the other interface, too. How can I tell why it sometimes takes so long until a imap process responds? Regards, Timo ---- Cyrus Home Page: http://cyrusimap.web.cmu.edu/ Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twiki List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html