[kortheo]

What are you referring to? What is their affiliation with Montenegro, and what is no longer optional?

Edit: Also in terms of incentives, is there another decent email provider that offers the same suite of services (end-to-end encrypted email that won't data mine you and serve ads to you?). That's still the main draw for me.

[Fnoord]

The country of Montenegro is the owner of the .me ccTLD.

Protonmail is proprietary (given the JavaScript served cannot be audited), and because it does not use an open standard.

Both Posteo and Tutanota are alternatives which don't profile you but whether they suit your needs is up to you. Hosted in Germany.