Abstract: A reply mail envelope to facilitate both as an outgoing and reply mailer. A front ply is affixed to a back ply so as to form a sealed envelope. Lines of perforations in each ply define an end portion of the envelope which is removable. The perforation lines in the front ply are offset relative to those in the back ply to provide an exposed marginal portion of the back ply. A return address flap loosely disposed intermediate the front and back plies has a first side edge affixed to the exposed marginal portion of the back ply. An insert is interposed between the front ply and the reply address flap. A second side edge of the return address flap opposite the first side edge is releasably attached to an undersurface of the insert. Upon removal of the removable end portion of the envelope, the insert is exposed so as to be easily grasped by a recipient. Upon removal of the insert from the envelope, the reply address flap releasably attached thereto follows.