If you have the productivity package you can recover permanently deleted emails within 30 days of deleting them. Click the "Actions for trash" icon next to the Trash folder and select "Recover Deleted Items" from the dropdown menu. A list of emails that can be recovered will appear. Select which emails you'd like to recover and then click "Move Selected Items". Next select which folder you'd like to move the recovered emails to and click "Move". A notification will appear confirming that emails were recovered.