[kureikain]

Postfix is really hard to run in container. Add rspamd, opendkim, opendmarc and I would just run them in their dedicated vm then.

[pratyushmittal]

Panubo has a pretty good postfix images for Docker. It handles most of the stuff:

https://hub.docker.com/r/panubo/postfix/

Source: https://github.com/panubo/docker-postfix