I've always read that hosting your own mail server is a pain. Not because of complicated tooling but because of security. Always wanted to try hosting my own. This makes me want to try even more.
You can start slow. Install the basics. Look into postfix and dovecot, deflecting spam, and the whole DNS stuff. If you feel confident in your setup, start using it for non-critical stuff first.
That's the beauty of it imo, you can do everything in your own time without deadlines.