Add lock application feature for Desktop Mail app. Leveraging encryption at rest (meaning a full data lock). One of the reasons I use a non-persistent session/browser is in case I suddenly lose access to my machine. I'd like a yubi key option too. You could use system auth scheme too (e.g. how you implemented FaceID and pin on the mobile app).

Similar to how Safari now has a private window lock, the app should do the same (so that if I lock the desktop, the app locks too and it has a time/interaction based lock). It should also operate as a kill switch, so that communication pulls are paused until unlocked (I don't need to pull for new emails until unlocked anyway), or have a notification passthrough (e.g. notify me there is something...but don't pull rest of data until unlock..then fetch).

An advanced feature should also be a Burn switch, so that in a pinch I can either remove or encrypt and destroy key for ANY locally stored data. Obviously it takes a few key strokes to delete the app, so it might be faster to move to a burn?>approve>burn flow (though if it can be speedily done, entirely removing the app is good too, but I think OS confirmations get in the way...like "this is running are you sure?"). But if I can simply click burn or key-combo burn or initiate from other session, and it just logs out and encrypts...then that is good too.