Today we happy to confirm that mailcow is completely usable with Debian 13 🎉🎉 However, during upgrade you may stumble accross some pitfall: Exim. For this, we wrote a guide:
You want to host mailcow on your own but do not know how? And you want to see the whole installation process prior before getting started? Then checkout the video from our community member Webnestify: Many thanks for the video! Highly recommended.