Method of processing postal articles for making up and separating delivery rounds

A method of handling mail items for sequencing simultaneously a plurality of delivery rounds in a sorting machine having N1 sorting outlets with interchangeable trays, each mail item having a postal address corresponding to a delivery point in one of said delivery rounds and each delivery round having a plurality of delivery points, said method comprising the steps of programming said sorting machine by assigning said N1 sorting outlets to said delivery points of said delivery rounds according to a certain sorting plan including a first and a second sorting pass and sorting said mail items towards said N1 sorting outlets by performing said first and second sorting pass, wherein said method further comprises the steps of:

• assigning said N1 sorting outlets to said delivery points according to a modulo N1 distribution, said plurality of delivery points of said plurality of delivery rounds being concatenated for performing said distribution,
• and during the second sorting pass of said mail items, detecting whether a first and a second mail item to be sorted consecutively towards a common sorting outlet correspond respectively to two different delivery rounds and in response to said detection, triggering a change of tray into said common sorting outlet to load said first mail item in a first tray of said common sorting outlet and said second mail item in a second tray of said common sorting outlet different from said first tray.