High security self-sealing mailing receptacle

A mailing device or the like comprising an envelope having a front and a rear face, said front and rear faces being connected at bottom and side edges, said rear face being of lesser vertical extent than said front face, said envelope including a mouth portion defined between the inner surface of said front face and the uppermost margin of said rear face, a closure flap defined by an upward continuation of said front face, said closure flap being connected to said front face at a first hinge line coincident with the upper margin of said front face, said closure flap extending laterally in each direction beyond said side edges, a pressure sensitive adhesive layer on the inner surface of said closure flap extending entirely across said closure flap adjacent the end margin thereof, a release strip removably secured to and covering said pressure sensitive layer, a length of high tensile strength material fixedly bonded to said inner surface of said closure flap at a position parallel to and interposed between said first hinge line and said pressure sensitive layer, said material extending entirely across said closure flap, a cutout portion formed through said closure flap and said tear strip laterally inwardly of and in proximate relation to one of said side edges, said envelope being sealable by removing said release strip, folding said closure flap over said mouth portion to bond portions of said pressure sensitive layer to said rear face, and thereafter folding the portions of said closure flap extending beyond said side edges into registry with said front face about fold lines coincident with said side edges and bonding said extending portions to said front face.