SSL connection reset by peer

[Timo Sirainen]

On 25 Jul 2016, at 18:26, Vince42 <dovecot at mx24.net> wrote:
> 
> Hi,
> 
> [Steffen Kaiser] - [2016-07-25 08:23]
>>> I am running a dovecot server and have set up an external monitoring,
>>> where every five minutes a login with SSL on port 993 is done. I usually
>>> get once a day an error "connection reset by peer - SSL connect", which
>>> goes away until the next monitor is executed.
> 
>> that looks like a basic networking issue to me.
>> Do you have logs how many users try to connect at this time? Is it
>> always the same time range? Is the server load very high?
> 
> My server has nice specs (in fact a 30 times lower scaled server never
> had this kind of problems), I also don't host many domains and users,
> therefore I doubt that some kind of limit might be touched. I also
> suspected some internal system load, but unfortunately the error occurs
> arbitrarily, which makes me think that no scheduled process is
> responsible for this. I also ran 'top' during such an event without any
> obvious load tasks. The system statistics also show no weird peaks. I
> read about the "running out of random" phenomenon, but during such an
> event there were still enough resources random-wise.
> 
> Could it be that I need to offer more login processes or that I should
> raise some of my configuration values?

If you are reaching any such limits, a warning is logged. Do you see any errors or warnings at all in logs?