1. A method for updating address data for a plurality of mailpieces processed by a document sorting system prior to delivery by a postal authority, the method comprising steps of: providing a client address list electronically to a service provider, the client address list not being supplied by the postal authority; forwarding the client address list from the service provider to an address service provider, the client address list being associated with the plurality of mailpieces to be processed on the document sorting system; updating at least some of the address data contained in the client address list for compliance with one or more regulations of the postal authority or any requirement of the client; converting the updated address list into a directory format required by an imaging system associated with the document sorting system and transmitting a client address service data directory to the service provider; storing the client address service data directory, associated with the plurality of mailpieces to be processed by the document sorting system; processing the plurality of mailpieces on the document sorting system; capturing an image of an address positioned on each mailpiece by the imaging system; comparing address information from the captured images of the mailpieces with the stored client address service data directory, which is not a directory based on data supplied by the postal authority; and for one or more of the plurality of mailpieces, printing corrected delivery information based on the comparison step, wherein the delivery information is printed as a postal authority approved barcode on the one or more of the mailpieces, to form one or more postal authority approved mailpieces.