strange delays in connecting to POP3 server

[Sandy Drobic]

Igor Belikov wrote:
> Hello Daniel,
> 
> In some strange reasons I don't receive your answer - only answer on
> answer...
> 
>>> Sounds to me like a DNS timeout issue. You might want to
>>> check your resolver configuration.
> 
> We have own DNS server on same computer, and I check logs carefully. I
> don't find any reason to suspect DNS. Moreover, I find following
> records in POP3 logs:
> 
> badlogin: aaaaa.bbb.lan [192.168.cc.dd] plaintext eeeee SASL(-13):
> authentication failure: checkpass failed
> 
> and I think that delays occur during this unsuccessfull logins
> 
> cyrus authorises users by MySQL database, and all works fine except
> irregular delays...
> 

Have you checked the number of concurrent SQL connections and compared it 
with the configured maximum of connections for SQL?

Sandy