Usps domestic return receipt form

sample of PS Form 3811

sample receipt

Available for an additional fee, only when purchased at the time of mailing.
Available for Priority Mail Express, Priority Mail, First-Class Mail, or First-Class Package Service* items when purchased at the time of mailing with Certified Mail, Registered Mail, Collect on Delivery (COD), Signature Confirmation Restricted Delivery, or insurance (more than $500).
Available for USPS Retail Ground, Media Mail, or Library Mail items when purchased at the time of mailing with COD or insurance (more than $500).