A thank you letter to customer for the order of product / goods.
The items are in stock, delivery will be made within [x] days [after receiving the payment]. [We believe you will [receive outstanding results] / [resolve the long-standing issue of [ISSUE]] from the use of [PRODUCT].]
[In addition, Sales is also beginning to take off for [ANOTHER PRODUCT] and we will see that you get advance information about it. What makes [ANOTHER PRODUCT] unique are [ADD ANY NEW OR UNIQUE FEATURES OF ANOTHER PRODUCTS – e.g. technology, integration, appearance, colour, storage, support, format etc.]. We hope you will find [ANOTHER PRODUCT] interesting too.]