If you decide to run everything yourself, Run Your Own Mail Server by Michael W Lucas is a recent and comprehensive book on the topic.

But for most people in your situation, email aliases (forwarders) do your domain pointed at an email provider is the best option. I’ve used this setup for decades. On top of being able to swap the back end when you want, you can also spin up aliases whenever you want, so you could decide each entity you interact with a different email address. That way if it starts getting spam, you know who betrayed you.

Currently, my top two email provider recommendations are FastMail and Proton.

My web host went from allowing a catch-all, so I could just make up aliases on the fly to making me configure each alias manually. So I also use MXRoute’s forwarding service to enable catch-alls on a couple domains. I used a coupon and paid for like ten years upfront.