How to fix the issue related to Exim incomplete transaction: you have to tune up timeouts in your e-mail client.

Today I’ve noticed a strange thing after Directadmin software update. Exim stopped processing e-mails, the thing that is really necessary for any server. I’ve started to look through log files to identify the problem. Here is what I have at the moment.
My mainlog (/var/log/exim/mainlog) is full of messages like this:
2008-10-30 19:27:02 exim 4.67 daemon started: [...]

On some servers Dovecot doesn’t start automatically after reboot. That is a fault of the system administrator, but if you need to bring it back working there is a solution, that seems to be effective with all instances of listen() failed.
Let’s take we’re trying to start dovecot and getting the following error:

Fatal: listen(993) failed: Address [...]

Today I went back from my short trip to the country. First of all I decided to check my mail, and when I did it, I got the following error in my E-mail client: !25.07.2008, 19:20:39: FETCH -ERR [IN-USE] Mailbox in use. That’s not the first time when such an error happens and I [...]