1. A computer-implemented process of tracking mail during postal handling at a postal processing facility, comprising: initially sorting an incoming stream of mail on an automated sorting machine to a series of pockets based on a sort scheme; during sorting, introducing RFID-tagged, machine-sortable markers into the incoming mail stream at intervals and sorting the RFID-tagged markers with the mail into pockets of the sorter; sweeping the mail and RFID-tagged markers from the pockets into trays, wherein the markers are introduced such that at least one marker is swept to each of a set of trays containing the sorted mail; transporting the trays containing the mail and RFID-tagged markers from the automated sorting machine; and during a postal operation subsequent to the initial sorting, scanning one or more of the RFID-tagged markers; and identifying mail from the initial sorting from the scanned RFID-tagged markers.