Go to your inbox. Touch bottom left corner, this will bring up a screen with all aspects for your mail including trash(deleted mail)Tick one box next to any message, this brings up a new screen at the bottom of your sceen, touch the multiple pages icon,this puts a tick next to the messages, touch the trash can icon and viola, most are gone. You may have to do this a few times. But it does get rid of the messages and they don't come back. If you have another computer linked to your mail delete the trash there as well. Long winded but it works.