The project looks cool! However, I think the hard part of self-hosting email is not the tech stack, it's getting email delivered to your recipients using Google or Microsoft severe email servers. It's hard to rent a server that IP address is not in a block that big email providers consider suspicious already or will soon. And any mishaps can get you locked out and you need manual intervention to be allowed again.
I used to self-host years ago but I've abandoned the idea now.
I used to self-host years ago but I've abandoned the idea now.