@lwpembleton I use Proton Mail, but have intentionally kept my VPN separate, using Mullvad.
An easy way to avoid a lock-in with Proton would be to register a custom domain using some cheap provider, and set up emails on that domain on Proton. Then, if you ever need to move, you just set the custom domain up on your new provider. https://proton.me/support/custom-domain