(UCS Version 5.2-1 errata38 / Dovecot 2.3.19.1)
We are running in an issue with Dovecot: From time to time, connected IMAP clients fail to display the list of messages in a certain folder. As an example: Thunderbird displays “No messages found” for this folder, while it displays all other folders. Interaction with the Dovecot server is possible, e.g. marking messages as read is handled by the server and shown on other clients.
There is no message in Dovecot’s logs. Restarting the IMAP client may display the messages in a folder, but hide other folders for the same user/client or a different one.
I assume that we are running into a limitation of the number of e-mail folders watched. We have about 150 GB of e-mail with only 10 users, but thousands of folders and multiple clients simultaneously active.
Is there any hint which parameter I could tweak?
Cheers, Rainer