Abstract: A separating device wherein two belts with different friction coefficients present respective straight portions facing each other and converging at a contact portion. The belts are fed with a number of mail items which are wedged in the V-shaped opening defined by the straight portions and are fed singly through the contact portion by the higher friction coefficient belt and to the input of a follow-up conveyor belt system. The device comprises a barrier of sensors located between the contact portion and the input of the conveyor belt system, and which provide for determining the form and spacing of the mail items. The signal generated by the barrier of sensors is used for adjusting operation of the higher friction coefficient belt.