I tried entering the address from the imap mail server provided by disroot and murena. However, this has no effect.

Then I tried to find information on the forum and in the documentation section of Kolab Notes. However, I only found a mention by one of the forum participants that Kolab Notes can be connected to Google mail. I didn't find any details.

Is it possible to connect these applications with free mail servers or do I need to run my own imap server with special settings?