A method of sorting postal items for preparing postman's walks on a postal sorting machine having an inlet and a set of sorting outlets includes loading a first batch of postal items and a second batch of postal items consecutively into the inlet of the machine, and directing the postal items of the first batch towards a first subset of sorting outlets, and the postal items of the second batch of postal items towards a second subset of sorting outlets that is separate from the first subset of sorting outlets; and while the postal items of the second batch of postal items are being directed towards the second subset of sorting outlets, reloading the inlet of the machine with the postal items taken from the first subset of sorting outlets, and, while the postal items of the first batch of postal items are being directed towards the first subset of sorting outlets, re-loading the inlet of the machine with the postal items taken from the second subset of sorting outlets.