Priority Mail is used for documents, gifts, and merchandise. Any mail-able item may be sent as Priority Mail. The maximum weight is 70 pounds. The maximum size is 108 inches or less in combined length and distance around the thickest part. Mark each package "Priority Mail" in the postage area or use a USPS-provided Priority Mail envelope or box.
Priority Mail offers 1-3 day service to most domestic destinations. Priority Mail envelopes, labels, and boxes are available at no additional charge at most post offices or by ordering from University Mail Service.
Priority Mail Flat Rate Envelope
$4.60, regardless of weight or destination, for matter sent in a Priority Mail Flat Rate envelope provided by the Postal Service.
Priority Mail is not a guaranteed service.