Ginko

Proton lost me when I found out you can't receive notifications from their app on a de-googled phone. Their app requires Google services for notifications. Since then I've moved to Tuta and am very happy with the service and notifications work. I mean how hard is it to set up a new email check every half hour in the app. What's the point of private email when you have to run it on a spyware (Google) infested phone.

There are many tutorials on YouTube. I recommend SpaceinvaderOne's tutorials. Very in-depth and easy to follow.