The service is solid, but there are a lot of caveats and compromises they make to achieve their differentiating features. For one thing, the encryption means you can only use their frontend/app to access your email. Unfortunately the app doesn't get notifications reliably, search is utterly broken, and the app can't show the subject line in toasts for security reasons, so I never know if an email needs to be read now or whenever's convenient.
You also need to be on the paying tier for a usable product. I evaluated a number of options when I was trying to decide where to park my domain long term. Cue an incident at a border crossing where immigration wanted to see a hotel booking that search insisted didn't exist. Turns out the booking email was a few days outside the free tier search window, and that limitation wasn't obvious in the pressure of an immigration queue. Felt like I had been gaslit once I realized.
You also need to be on the paying tier for a usable product. I evaluated a number of options when I was trying to decide where to park my domain long term. Cue an incident at a border crossing where immigration wanted to see a hotel booking that search insisted didn't exist. Turns out the booking email was a few days outside the free tier search window, and that limitation wasn't obvious in the pressure of an immigration queue. Felt like I had been gaslit once I realized.