Am 28.05.2016 um 21:25 schrieb Vince42:
Hi,
from time to time the IMAP login times out ... my external monitoring says "connection reset by peer (SSL)" and Thunderbird tries to connect forever. After a short while everything returns back to normal operation.
The system resources are plenty, there are no error messages and no greedy background tasks running.
I read a little about tweaking imap-login - but all the default parameters seem to be set more generously than what was recommended.
Where should I start the debugging process?
I really wish there was some "dovecot optimizer tool" ... :P
That sounds suspiciously as if you are running out of entropy. Is that a virtual machine you are running with dovecot?
At time when the SSL connection cannot be established check the value of available entropy by
cat /proc/sys/kernel/random/entropy_avail
In case you see a low value you should consider running a daemon like haveged.
Alexander