Inform customer that items on back order have arrived and tell them when they might expect delivery and confirm price. Always thank them for their business.
1234, Main Street
Boston, MA 02123
08 April, 2005
<Recipient Address Goes Here>
I'm pleased to inform you that the <merchandise/items/products> that we had on back order <have/has> arrived, and we are currently in the process of filling your order, <reference to order> of <items ordered>. We will <method of delivery> as soon as it is ready. We expect your order to be complete by <date>.
The total charge, <including shipping>, will be <$price>. We appreciate your patience and look forward to serving you in the future.
encl: <List of enclosed items goes here>