Tape may not be used on registered mail if it does not damage the envelope or wrapper when removed, or if it does not absorb a postmark impression. Certified Mail service provides the sender with a mailing receipt and a record of delivery to the addressee. Only mailable matter on which postage at the First-Class or Priority rate has been paid may be accepted as certified mail. No insurance coverage is available for certified mail. See item 4. for cost of return receipt.
Insured mail is dispatched and handled in transit as ordinary mail.
Return receipt service furnishes a mailer with evidence of delivery. After delivery, the Postal Service mails the return receipt to the sender. There is no minimum weight limit for Priority Mail. The maximum weight limit is 70 pounds. Priority Mail is primarily a two day delivery process but it is not guaranteed for two day delivery.