Abstract: A signal device for a mailbox or similar roadside receptacle has an abutment member received in the box on its bottom wall in position to be engaged by mail, or some other article, and thereby moved to the opposite end of the box. The abutment member is secured to a rigid rod extending through the rear of the mailbox and carrying a signal flag outside the box. This rod is inclined to the bottom wall of the box so that as the abutment member is engaged by the mail or other article, the signal flag is moved laterally of the mailbox so that it may be more clearly seen from a distance than when it is possibly concealed by the perimeter of the mailbox when closely proximate the adjacent end of the mailbox.