A: It sounds like you are wondering if the party you sent the letter to will later deny having received the letter. In a non-judicial setting one of the best ways to track and have proof of delivery is to send it by US mail with a return certificate signed by the recipient of the letter. The post office has the forms needed and will guide you thru the process. It is more expensive then normal delivery but it will give you what you seek. The most expensive way is thru a process server, who will personally serve the letter for you. You can find them on google for your area and they will quote a price for this service