delete email iphone 6s

[iMore Question]

The answers provided here and elsewhere are the same , but doesn't work on my Iphone 6s
When I follow the steps to edit (the button is at bottom right not st the top, but shouldn't make a difference) press button by top mail and hold down the Move button, there is nothing that says
Mark All. Mine only has Mark, Move, and Trash, all of which are greyed out, when so release as directed. please, please help

 

[josepilot81]

I have the same issue there!!

 

[Ledsteplin]

You can't delete all in Mail on the inbox. They had that for a while, but got complaints. So it was removed in iOS 10. You can still delete all in trash.
So you have to mark each email individually to send to trash. It's easier to swipe left and tap trash.