As a current user of Kopano, I am starting to test different alternatives now.
My first test is mailcow, which has support for keycloak in its nightly builds now. I hope the feature while hit stable soon. I have currently installed mailcow on a separate ubuntu server, so not as to overcomplicate things (for now).
I have tried the original mailcow post to set up: 🔒🔑 External Identity Providers for User authentication - mailcow: dockerized - Blog
However, when I click “Test connection” i get an error. If I save anyway and try to log in to mailcow, I get “login failed”. However, when I turn on logging in keycloak, the login shows as successful.
Any help would be very welcome to debug the situation further.