Embodiments of the invention relate to systems and methods of correlating data relating to an item of mail, such as barcode information, with the associated item of mail. This allows the item of mail to be sorted using the data relating to the item of mail. According to one embodiment of the invention, a method is provided for correlating an item of mail, subject to sorting by a mail sorter, with data, stored by a processing unit, relating to the item of mail. The method comprises acts of associating the item of mail with a first counter value, associating the data with a second counter value, and corresponding the first counter value with the second counter value to correlate the data with the item of mail.