Abstract: A transposable dual mode mailbox signaling device for mounting on either side of a rural mailbox is disclosed. A housing attachable to either side of a mailbox proximate the mailbox door has a front face, back face, a proximal end, including a centered elongated aperture to receive a flagstaff flange, and an open distal end, an open top edge and an open bottom edge. A longitudinally symmetrical flagstaff is mounted within the housing for pivotal movement about its horizontal axis. The flagstaff has an opposing pair of horizontal flanges at the lower end as well as a downward projecting flange at the flagstaff's lower edge. Each flange is sized to fit through the proximal edge's aperture. A longitudinally symmetrical flag is attached to the flagstaff's other end. A reversible rod attachable to a mailbox door includes a detent to retain a corresponding horizontal flange when the flag is up.