Certified Mail provides the sender proof of mailing. With electronic USPS tracking, the sender is notified when the mailing was delivered or that a delivery attempt was made. An Electronic Return Receipt showing the recipient's signature is also available.
Unlike Registered Mail, Certified Mail is sent together with regular mail. Although, it is not as protected, Certified Mail is delivered much faster and usually takes about a week.
Once a Certified letter is submitted via PostSeal, USPS tracking number will be automatically emailed to you.
Unfortunately, the service is only available for mail sent domestically within the United States.