This is an old one and a personal annoyance to me. The UI of the email app has a different direction than all the other jolla/SFOS apps.
Ie you tap something in the settings, you move to a page right and if you want to go back you swipe LtoR.
In the email app you are presented with your inbox BUT if you want to go to another folder (send,deleted etc) you have to swipe from RtoL.
For the sake of consistency this needs to be fixed.