Do you have a write-up about this? I've been wanting to host my own almost entirely for the extra control over incoming mail and have been held back by the same worries. I'd like to see what a success story looks like.
Underneath though, it's a pretty standard Postfix + Dovecot setup and there are plenty of those around.
[0]: https://docker-mailserver.github.io/docker-mailserver/latest...