Method of sorting pre-sorted mailpieces

A method of sorting mailpieces in a postal sorting machine, said method comprising the steps of:

• loading the mailpieces into a feed inlet of said machine;
• unstacking the loaded mailpieces one-by-one to cause the loaded mailpieces, in series, to go past a camera that forms a digital image of a current mailpiece that includes a delivery address thereon;
• causing a monitoring and control unit of the machine to:
• automatically read delivery address by optical character recognition (OCR) on the basis of the digital image of the current mailpiece,
• compare the result of the automatic reading with a reference database so as to evaluate the delivery address that corresponds to the current mailpiece, and
• direct the current mailpiece automatically to a corresponding sorting outlet of the machine based on the comparison;
• detecting a loading in the feed inlet of the machine of a batch of mailpieces pre-sorted by a mailer of the batch of mailpieces, the batch of mailpieces having been pre-sorted on the basis of the respective delivery addresses of the mailpieces;
• and
• in response to the loading in the feed inlet of the machine of the batch of pre-sorted mailpieces being detected, causing the monitoring and control unit to load, in the reference database, a lexicon comprising the delivery addresses for only the pre-sorted mailpieces of the batch, wherein the monitoring and control unit, for each current mailpiece of the batch of presorted mailpieces, compares the result of the OCR reading with the delivery addresses of the lexicon so as to detect similarity in order to evaluate the delivery address of the current mailpiece of the batch of presorted mailpieces.