In the wake of Proton's CEO losing his GD mind and Tuta trying to to be a square circle about generative AI, I've seen a lot of folks looking for new email provider. And I saw a rec for a service but it didn't let you use your own domain.

Nah.

Very seriously: Get your own domain.

Do it. Yes, it's an added yearly expense. The old ones (.com, etc) are still the cheapest.

When your email provider descends to psychotic fascism, you can move service without having to change your email address.