A method for sorting mail items (6) using a dynamic resource allocation process and an overbooking mechanism whereby an overbooked sorting destination (D) is substituted for another sorting destination already assigned to a certain sorting output (S), comprises the steps: a) of identifying (27) from among said sorting outputs (S) a sorting output that has a fill level (N) above a first threshold (s1) and the oldest storage activity and of assigning (29) this sorting output to the overbooked sorting destination; b) if all the sorting outputs (S) have a fill level (N) below said first threshold (s1), of identifying (32), from among the sorting outputs, the one that has the oldest storage activity and of assigning (34, 37) this sorting output to said overbooked sorting destination and of indicating (36, 39) that said other sorting destination is a sorting destination to be consolidated.