I do believe that the SourceHut project is investigating ways of simplifying the process of self-hosting email, for the purpose of using it to power a self-host

I do believe that the SourceHut project is investigating ways of simplifying the process of self-hosting email, for the purpose of using it to power a self-hosted forge platform. I feel like there's a decent chance of a large overlap in needed features and goals. The SourceHut folks are highly reachable on Freenode in #srht and other places.