I tried Proton, even paid for a year. But hot damn the Android app is garbage. So I’ve moved to Fastmail and I like it a lot. The app is snappy and I love that it has calendar, contacts, mail, notes, and files storage all in the same app. I used a custom domain with Proton so wasn’t hard to switch to a different provider. Just wish I would’ve known how bad the mobile app was before I plunked down the money.