Important Information for Sending Mail 
Return Receipt:
Return Receipt can only be used when it’s Certified mail, Insured or Registered. The only time it can be used by itself when it’s a merchandize then the brown form will accompany the green Return Receipt form.
Delivery Confirmation:
Delivery Confirmation can be used with priority mail or Standard . It can also be used on certain First Class depending on its thickness. It only tells you when and where a package was delivered.
Registered Mail:
Registered Mail cannot be sent in bubbled envelopes when it’s domestic, but it can to International country.
Express Mail:
Express Mail is guarantee 2-day delivery.Postage can be claimed when it’s not delivered within two days.