From a Home screen, tap Apps (located in the lower-right).
These instructions apply to Standard mode only.
From the Inbox, touch and hold the appropriate message.
Selected when a check mark is present.
If desired, select additional messages to delete.
Tap the Delete icon (located in the upper-right).
To delete several or all messages at once, refer to Delete emails & recover from Trash and click Computer then choose the desired option. This process can't be completed from the mobile app.