Backorder - add backorder comment on customer order email

We allow backorders and with the Zoey options our website clearly displays if an item is on backorder. BUT quite a few customers somehow overlook this when purchasing from our website. 

It would be great if Zoey could add to customer order emails 'on backorder' next to any affected products. This would be another step that the customer has a chance to realise if they missed it earlier and also a help to me as it would confirm that when the customer purchased the item it was being displayed correctly.