Sample Reply letter to an previous order.
Sub (Dispatch of goods as per the work order)
We bet to thank you for your kind order of the ____________(date) and have the pleasure of advising dispatch of the books stated therein by rail today. You directed us to send the books per V.P Post; but considering their large number we have thought it reasonable to send them by rail as it will lessen the cost. We hope you will approve of our action. The R/R is sent under a separate cover per Registered Post. Awaiting the favor of further orders.