Install for Improvements to the Mail App
Apple made some notable changes to the Mail application in iOS 13.4 and you'll get them in iOS 13.5 if you skipped iOS 13.4 and iOS 13.4.1.
The Mail app has a new toolbar design that moves the compose icon to the far right and the delete icon to the far left. The reply icon and folder icon sit between these two.
Because the new design moves the reply icon away from the delete icon, it should make it hard to accidentally delete an email.
It also adds Folder and Compose icons.