Mail is returned to sender:

• If it does not bear a sufficient address;
• If the addressee has moved without providing a forwarding address;
• If it is refused by the addressee;
• The postage due is not paid by the addressee on demand (no return address shown on cover.)

Depending on the type of mail, the cost to the mailer can vary from a no charge, a fixed or negotiated amount or an amount equal to the original postage.