Abstract: An envelope feeder sequentially feeds envelopes from a loading station to a printing station of a conventional printer for addressing, and releases addressed envelopes at a discharge station. The feeder includes an upstanding housing that journals a platen roll at its lower end and an idler roll at its upper end. The feeder's platen roll replaces the printer's conventional platen roll and serves to drivingly connect the feeder to the printer. The housing has a front guide surface that faces forwardly with respect to the printer, and a rear guide surface that faces rearwardly. At least two transport belts have reaches that extend along the front and rear guide surfaces. The belts extend around and are held taut by the feeder's platen and idler rolls.