Start with buying your own domain.

If you are interested, self hosting email has an outdated bad reputation, I have had much more problems with google blocking microsoft email from custom domains than from self hosted emails.

That said, it is still a lot of work. For a hands off system, find a national provider that can use your domain, so you can switch later while retaining your address.

Self-host if you care about privacy and tech ethics, otherwise whatever seems most stable.