I got suprised with this [1]. Still I did not tested, but looks promising. You know about that project? I liked a lot: - Documentation / wiki [1] - Completeness - The tests! [2] I'm not very aware of the freedombox capabilities. Hope is useful. Cheers! [0] https://github.com/tomav/docker-mailserver [1] https://github.com/tomav/docker-mailserver/wiki [2] https://github.com/tomav/docker-mailserver/tree/master/test