Add delete option for mail that is in trash
On the web version of Proton Mail when you click on an e-mail on the left side of the screen there are 4 icons (a envelope, a archive box, a trash can, and a star).
If the message is already in the trash, could the the trash can icon change to the delete icon and allow the user to permanently the message (after giving a warning message).
Brian shared this idea
Kava Blanca commented
Yes, Yahoo mail displays an Empty Trash icon when hovering over the Trash folder.