Thank you Ivan,
You are the winner :)
Users are happy in the last 1 hour, so, I assume the maxchild did the trick.
The old server has no this kind of limit, so, never had this issue.
Now we have 118 connections, 140 processes, which a little bit higher than the limit, so, that explains the frequent, but not a permanent connection timeout.
Fortunately, regarding to Vladas' reply, we had no problem with identities (users have absolutely no idea, what is it, they are normal and nice people :).
The copy also caused by this lack of imapd processes.
So, if somebody has mysterious connection timeout issues, check the process and connection numbers and compare with maxchild in the cyrus.conf.
(after turning off csf/lfd firewall, debugging network, fixing windows dns issues and ldap plugin issues and a lot of other, but completely unrelated fun tasks :))))
Cheers,
István
2022. 11. 15, kedd keltezéssel 12.53-kor Ivan Kuznetsov ezt írta:
HelloIt can be a lack of available IMAP handlers. One TB makes more than oneIMAP connection depending of a number of tabs opened. Some clientconnections can hit a limit of running imapd processes. Consult withcyrus.confRegards, Ivan
