[Dovecot] high number of processes

[Timo Sirainen]

On Tue, 2011-06-14 at 21:34 +0200, Egbert Jan van den Bussche wrote:
> Hi,
> 
> Sometimes a script kiddie tries to guess passwords on our mailserver
> (Ubuntu 10.04.2 LTS, postfix, dovecot 1.2.9, scanners, the standard
> stuff). That leads to a nagios message about the high number of
> processes. The number goes above 500. 

What processes are they?

> Nagios threshold is set to 250,
> which is more than enough for normal operation of this server. When are
> these processes supposed to die again? They seem to stay at the high
> count quite long.
> 
> Is there a way to limit the generation of extra login processes? Can I
> tune the login_process... params a bit? I have then all on default.

With defaults you shouldn't get more than 128 login processes, so I
don't know why they would go to 500.
http://wiki.dovecot.org/LoginProcess anyway may be helpful.