Swiping may be a nice gimmick for youngsters, where mistakes don't matter. But for me when trying to WORK outside the office with this app, it turned out to be dangerous.
There are two functions when swiping to the right, which are physically very nearby: beginning from outside the left edge and from more within the notice. The result is very different as known. In the first case you get the folder list, in the second case you definitely delete the message.
I intended the first use. But the smartphone is in a hard cover, which is a little bit higher than the screen on both sides. So by accident a swipe didn't touch the screen at the very outer edge and instead of showing the folder list, an important message had been gone FOR EVER.
It's good to have still kmail running beside the app on the PC. But I am not sure, for what the app is then useful. Permanent delete should be a bit more protected.