Pickoff mechanism for mail feeder

A pickoff system for removal of mail pieces one at a time from the end of a stack includes a pickoff belt mechanism, a sensor positioned to determine mail piece movement speed, and a measurement device determines belt movement speed during operation of the pickoff belt mechanism. A vacuum system includes a vacuum pump and a vacuum manifold positioned to apply suction to the mail piece in a direction that tends to hold the mail piece against the belt of the pickoff belt mechanism. A controller is configured to compare the belt movement speed and the mail piece movement speed during operation, and when mail piece movement speed is slower than belt movement speed, indicating slipping of the mail piece relative to the belt of the pickoff belt mechanism, the controller temporarily increases suction force applied to a mail piece being transported by the pickoff belt mechanism.