A storage module for flat postal items includes a storage area, an infeed function to transfer postal items from a stream of postal items into the storage area, and an extraction function to extract postal items from the storage area. The infeed and extraction function have a common roller conveyor unit and a feed stop. The infeed function guides the postal items in a direction of travel of the roller conveyor unit from the roller conveyor against the feed stop for a transfer into the storage area. The extraction function extracts the last stacked postal item from the storage area in the direction of travel of the roller conveyor unit through an extraction opening. The storage area includes a separating knife to exert a first pressure and a second pressure.