The USPS Certified Mail service provides the sender with evidence of sending as well as proof of delivery. Because Certified Mail is utilized for laws and regulatory purposes, it is essential to be able to offer documentation or confirmation that a Certified Mail letter was delivered. Certified Mail provides the sender with evidence of sending in the form of a postal receipt as well as electronic certification that an item was received or that a delivery attempt has been made on request. The United States Postal Service provides a registered mail option as an add-on service for First Class or Priority Mail shipments. Registered Mail offers end-to-end security In sealed containers. Registered Mail security records are kept but are rarely given to customers until a claim is made.