Scan all IMAP folders

I am filtering mails on the server side on my own server using Sieve and on GMail using filter rules.

While my other mail apps are able to scan all folders of an IMAP account, emClient does not have an option like this and as a result the Unread folder shows only some mails (and even some that are already marked as “read”).

Is there an option to enforce proper scanning of the IMAP folders?

PS: I tried to create a ticket via support, but they asked me to pay 10 USD for having support for one year. n/c.

Am I really the only person, who has the problem that the IMAP folders are not scanned?
This is really weird … :crazy_face: