Abstract: The shipping envelope comprises a forward panel and a rear panel closed along their side edges and a first bottom edge, with their second opposite edges free of each other to provide access to the interior. Each panel has an interior face and an exterior face, the forward panel being longer than the rear panel to form a foldable flap. Adhesive is applied to the exterior face of the flap and to the exterior face of the rear panel except for the marginal edges, and release sheets cover the adhesive areas. In use, the release sheet is first removed from the rear panel and the latter is pressed against a package to attach the envelope in place. One or more shipping documents may be inserted in the mounted envelope at the same or different times with the marginal edges of the rear panel allowed to bend upward to allow the envelope to accomodate the thickness of the documents.