is certified mail number also article number?
Each letter contains a unique Certified Mail article number that is 21 digits long and the number is express as a bar code on the outside of the letter beginning with a â94, 70 or â71â² article number. These article numbers match back to an electronic file used to print the Electronic Return Receipt PDF file. This provides the sender a fast and easy way to store âCertified Mailâ Electronic Reports that provide proof of mailing and USPS letter delivery confirmation. Using a Certified Mail Envelope with Electronic Return Receiptâ¢ provides the âin-routeâ letter tracking and the final letter delivery scan for each letter.