glokk

Apart from the kick-out risk, using SSO from Google/Facebook isn't good for your privacy neither. They usually have an iframe in their SDK that can track you even when you don't click on the login button.

Once you have your domain, you can use Zoho create emails for your domain for free. They don't offer IMAP/POP3 access in the free tier though.

There's another privacy-focused SSO solution from SimpleLogin that creates a different email address for each relying party.

You can use SimpleLogin [1]. It's available as a web app, Chrome/Firefox extension or iOS/Android app.

[1] https://simplelogin.io

Another solution is to create a different email address for each website/newsletter. This can be done quite easily with services like SimpleLogin or 33mail. This solution also makes this harder to track you online, therefore protect your privacy.

You can use an email alias service to create a different email address for each service. You can just disable or remove this address to unsubscribe from a service. SimpleLogin, 33mail do that.

If they have control over DNS, could they just move to another cloud service?