There are many services that will host your email with your own domain, and they hand hold you on what and how to change DNS to make that happen. It's not free

There are many services that will host your email with your own domain, and they hand hold you on what and how to change DNS to make that happen. It's not free, but then, why would it be? If you want to own your id in a decentralised system, you should expect to either host it yourself or pay a fee. If you want free, then you need to understand that you pay for that service by not owning your id (and probably get bombarded with ads etc...). I don't think that's unfair, and at least there is space for the former, contrary to the current social "networks".