ListWare is a address hygiene and list maintainance tool. ListWare updates your existing data through USPS approved services like NCOA, LACS, DSF, and CASS. It can also append phone numbers to your list. ListWare formats your data for processing, zips your data, and emails it. Melissa Data will perform the service you requested, then email the update file back to you. ListWare will overwrite the old data and print out reports. The software is FREE, you pay for the service only.