A mailing machine base adapted to have a postage meter mounted thereon, wherein the meter includes a printing drum and a drive gear therefor, and wherein the meter includes a shutter bar mounted for movement into and out of locking engagement with the drive gear to respectively prevent and permit driving the drive gear and thus the printing drum, the mailing machine base comprising, framework, structure for moving the shutter bar out of locking engagement with the drive gear and then moving the shutter bar into locking engagement with the drive gear, the moving structure including a lever arm pivotally attached to the framework and adapted to be disposed in bearing engagement with the shutter bar when the meter is mounted on the base, the lever arm including a yoke portion depending therefrom, the moving structure including a cam shaft journaled for rotation to the framework, the moving structure including a cam connected to the cam shaft for rotation therewith and having an end portion thereof disposed within and in bearing engagement with the yoke portion, the moving structure including a first pulley connected to the cam shaft for rotation thereof, the moving structure including a d.c. motor having an output shaft, the moving structure including a second pulley mounted on the output shaft for rotation therewith, and the moving structure including a belt looped about the first and second pulleys for transmitting motor drive from the output shaft to the cam shaft, structure for controlling the moving structure, and the controlling structure including structure for driving the motor in one direction to move the shutter bar out of locking engagement with the drive gear and for driving the motor in the opposite direction to move the shutter bar into locking engagement with the drive gear.