Abstract: A mail piece stacker system includes a back wall and a side wall. A platform is mounted adjacent to the back wall and side wall and is moveable in a vertical direction. The platform is adapted to support a stack of mail pieces, such as mail pieces, and has means connected to the platform to position the platform in a first vertical position when no mail pieces are on the platform and to position the platform in a different vertical position lower than the first vertical position when mail pieces are on the platform. The platform may be positioned at an acute angle with respect to the back wall and the side wall to help in registering mail pieces being stacked on the platform. The stacker may employ the method of moving mail pieces seriatim onto a platform. The platform is moveable in a vertical direction and is moved in a downward direction as mail pieces are stacked on the platform.