In iOS 13 (in this case on an iPad) the delete button in ‘Mail’ has been removed. The most used button for email I’d suggest!
Now to delete you have to go to either ‘Move’ and find delete, or via the menu options at the bottom right.
But strangely, with some select email the delete button reappears at the top right. Go figure.
Anyone know why? and if there is a way of getting delete button back?