Prosource is an accredited Postal Address Management Service Supplier (PAMSS) of the South African Post Office (SAPO). The PAMSS grading system was established by SAPO to entice bulk mailers to improve on address quality, thus assisting SAPO in optimising postal delivery. Through the use of approved PAMSS software, bulk mailers are able to clean their address databases and receive a statistical analysis and quality rating for their database. SAPO incentivises bulk mailers who meet their minimum requirements, i.e. a grading of at least 97% accuracy on their mailing lists, by offering them postage rebates per envelope mailed as well as, in some cases, upfront discounts. In order for the bulk mailer to obtain the rebates, a certificate indicating the percentage of clean records must first be applied for by a PAMSS, such as Prosource.

The major benefit of PAMSS address cleaning lies not in the incentives and rebates offered, but rather in the increased deliverability of mailed items and the reduction of return mail, ultimately resulting in a huge saving on wasted postage and production costs, and better overall client response rates.