I use an iPad which was designed to use the touch screen for typing in all kinds of positions. I feel the buttons on the bottom of the Proton mail inbox and the composition page are a hazard. For filing emails sometimes a button is touched by mistake. The email suddenly disappears and you have to waste time hunting for it in your myriad of folders. If possible move those controls to the top of the page where they are safer. I believe filing will then be more efficient with less misfilings.