FC3 / Courier-imap resource issue
Last weekend, I upgraded our mail server from FC2 to FC3. I also upgraded to the latest release of courier-imap. Since then the whole environment has had problems. I have downgraded courier-imap which had no beneficial effect and have upgraded to the 2.6.9-1.724_FC3 kernel.
The issue is that after a number of hours, it varies from 4 or 5 to a day, the imap daemons stop processing commands. It is possible to initiate new sessions but access to the maildirs seems to just hang, the client eventually getting a timeout or server not responding error.
Restarting the courier-imap service does not fix the problem but rebooting the server does (for a while).
The 3.0.3 version of courier-imap had been running fine on FC2.
I desperately need some help to try to resolve this problem, I will be rebuilding an FC2 disk over the coming weekend but would prefer to stay with FC3 if the problem can be identified and fixed.
So far I have had no response from the courier-users mailing list and as downgrading made no difference I suspect that I am exhausting a kernel resource but I don't know how to confirm this.