A Commercial Mail Receiving Agency (CMRA) is a private company that rents out private mailboxes. A CMRA, also known as a mail drop, typically operates as a Private Mail Box Operator. Addresses at a CMRA are therefore given the designation "PMB" (private mail box) instead of "PO BOX" (Post Office box).
A customer of a CMRA can receive mail and other deliveries at the street address of the CMRA rather than the customer's own street address. Depending on the agreement between the customer and the CMRA, the CMRA can forward the mail to the customer or hold it for pickup.
A customer may wish to use the services of a CMRA for privacy. For example, a person running a home-based business may not wish to divulge the home address. Alternatively, a customer in one community may contract with a CMRA in another community with a better known or more prestigious address.