ProtonMail has a free tier. It's definitely not the same level of service as Gmail, but I prefer it to being so dependent on the big G juggernaut for a critical service.

Downsides:

* spam detector is a bit aggressive, sometimes legitimate emails make it in there.

* features are limited unless you pay.

Full disclosure: I pay for their Plus product. My rationale is that I pay twice as much per month for Netflix yet email is hugely more valuable to me than Netflix is.

More full disclosure: I used to work for Google. That's part of what made me move from Gmail.