I'm currently on one of the large IT company's email provider. It's driving me nuts as it's constantly thinking there's suspicious activity on my account, probably because I'm using TOR, and then challenges me with a code it texts to my phone. And then every once in a while it thinks my password might be compromised and makes me change it. I never want to be forced to change my password. I will handle the security (password) for my account.

They also read my email as I've received calendar reminders of an upcoming flight and there's no way they would have known that without reading my email. They of course think they're doing me a favor, but I don't need any favors from them. I'd rather they not have access to my emails.

And I don't mind paying a reasonable amount for a good secure email provider who believes in privacy.

I found this site and it appears to have some good info:

https://restoreprivacy.com/email/secure/