I’ve been using ionos.com (formerly 1&1) and so far their support has been great and the price is pretty good. They originated in Europe, but have long ago since moved to the US and have datacenter in both the US and Europe. I chose them because I wanted something cheap with unlimited bandwidth and this ticked those boxes.

Private and federation are mutually exclusive concepts. Private instances are ones that intentionally don’t federate - like a private company community that’s locked to their intranet. For self hosted Lemmy instances you just need to close registration. Then since no one can apply, the only use case for email becomes the Forgot Password button for if you forget your password and at that point you’re better served with a password manager.

This sounds like a great idea