Abstract: A vacuum deck for a mailpiece insertion module including a plurality of friction drive belts, a support plate slideably supporting the drive belts, a repositionable backstop assembly disposed along the feed path of the envelope for arresting the motion of the envelope when disposed in a first position and permitting the conveyance along the feed path when disposed in a second position, a means for developing a pressure differential across the envelope for urging the envelope into frictional engagement with the friction drive belts, and a breaker plate disposed over and across an upstream portion of the friction drive belts to reduce friction drive forces developed along an upstream end portion of the envelope. In another embodiment of the invention, the pressure differential means is bifurcated such that the pressure differential developed across the breaker plate is lower than the pressure differential developed along the support plate and downstream of the breaker plate.