An apparatus for handling mailpieces produced by a mailpiece insertion system, comprising at least one mailpiece stacking assembly and a combination support/conveyor deck. The mailpiece stacking assembly accepts a plurality of mailpieces, i.e., as they are created by a mailpiece insertion system, and aligns the mailpieces to define a mailpiece stack. The support/conveyor deck is operative to convey mailpiece containers along a mailpiece handling path and includes loading and transport sections. The loading section is, furthermore, adapted to alternately reposition each of the mailpiece containers from an in-plane position to an out-of-plane position relative to the mailpiece handling path. The in-plane position is operative to transport the mailpiece containers along the mailpiece handling path while the out-of-plane position is operative to spatially reposition each of the mailpiece containers for alignment with a side edge of the mailpiece stack. That is, the loading section is capable of repositioning the mailpiece container such that its open end is proximal to and ready to receive the mailpiece stack. A loading mechanism is then employed to engage a side edge of the mailpiece stack for urging the stack into the open end of the mailpiece. That is, when the loading section has accurately repositioned the mailpiece container into alignment with the mailpiece stack, the loading mechanism may then displace and load the stack into the container.