The selected Proposer must provide insertion and mailing services with capabilities that include, but are not limited to, the requirements listed below. i. When required, insert the correct inserts and/or return envelopes into the envelope containing the bills and/or notices, ensuring all necessary materials are included. ii. Shall have Coding Accuracy Support System (CASS) certification with the United States Postal Service (USPS). iii. Utilize the best postal rates using various discount programs including, but not limited to, presort, bar coding of mailing addresses, and carrier route sorting. iv. Provide a detailed plan on how the proposer will ensure that ATC receives the lowest possible postal rates. This should include information on the minimum quantities required for mailing to achieve these rates. v. Provide National Change of Address (NCOA) services to include address standardization, address updates, and return codes via an interface file service for Unsecured Tax Bill Demand Letters. vi. Provide an interface file to upload and update accounts where there has been returned mail and/or an updated address for unsecured bills in enforcement...