Hey everyone,
Recently, I wanted to set up Mailcow as an OAuth provider for all of my services. Unfortunately, this did not really work out, because Mailcow does not support OpenID connect.
Because of this, I set up to use it as an authentication proxy. Since Authentik also had some troubles connecting with Mailcows OAuth, I submitted a pull request to implement Mailcow support, which just got merged:
goauthentik/authentik2380
Now, it is super easy to integrate Mailcow and Authentik:
Mailcow | authentik goauthentik.io
And since Authentik supports a wide variety of services and protocols, it is now possible to connect almost any service to Mailcow SSO 
Regards,
Dorian