To delete all emails on an iOS device, select the Edit button in the inbox, and tap a single email to highlight it. While holding down the Move button, deselect the email, and then release both fingers and tap the trash folder to move all emails into the trash.
- Open the Inbox
Tap the Mail application on the iPhone home screen to access your email. Select the Inbox option to view and edit the contents of your email inbox.
- Use the Edit and Move buttons to select all emails
Tap the Edit button, and select any one email to highlight it. Place and hold a finger on the Move button. While holding that finger down, use another to deselect the highlighted e-mail. Release both fingers to select all emails in the inbox.
- Move all emails to the Trash folder
While all emails remain selected, tap the Trash folder icon to move all of the contents of the Inbox folder to the Trash folder.
- Open the Trash folder, and delete all emails
Tap the Trash folder icon once again to view the contents of the folder. Select the Delete All button to empty the Trash folder of all emails and permanently remove them from your iPhone.