what is the difference between certified and registered mail
Registered mail can only be sent from the post office, but you can send certified mail from your office and other mailing locations, provided you include a sufficient amount of postage to cover both the certified mail fee and the postage for the mail class of your envelope or package.hoose certified mail when you need proof of delivery and time is of the essence. Registered mail is the Postal Service's most secure form of mail delivery, involving an unbroken chain of custody.