This. The hard part of hosting your own mail is emphatically dns and deliverability. Mail-in-a-box does all of the dns magic to ensure folks get your email. The rest is gravy.

MIAB is a great piece of software. I've been using it for a little longer than two years and it's a pleasure to use. Updating is easy and I've had no problems with it since the first install. It is rock-solid and reliable.

And also http://mailcow.email if you want something to quickly spin up in Docker with a bit more configuration available