1 Certified Mail - $3.30 Fee (All fees are in addition to postage.). 2  Certified Mail provides proof of mailing and delivery of mail. 3  The sender receives a mailing receipt at the time of mailing and a record of delivery is maintained by the Postal Service. A return receipt can also be purchased for an additional fee to provide the sender with proof of delivery. 2  Certified Mail service is only available for First-Class Mail or Priority Mail. 3  See below for more information about return receipts. 4  An example of a Certified Mail Receipt is shown below.