Business Reply Mail (BRM) is a service from the U.S. Postal Service in which a sender provides a prepaid postage envelope or card to the recipient. Business Reply Envelopes or postcards can help you get paid on time, of course, but they can also be used in a variety of ways. They are often used by companies and businesses for marketing purposes. The company sends a postcard or an envelope to prospects who then fill out the information and send it back in to the company at no