A convenient use of the contacts feature is that it keeps all the orders from a specific customer all in one place.
To view these past orders, first access the contact by clicking on the Contact icon then the contacts tab.
After you've selected a specific contact, click on the E-Commerce tab and you'll see their past orders in a list. From here, you can click on the order number to see the order details.
After you click on a specific order in the list, you can view the status history of the order, change the payment status and resend receipt if needed.