Unique Mailing Systems 860 Napa Valley Corporate Way, Napa, CA94558 Unique Mailing Systems serves as middleman between businesses and the post office. Its bulk-mail house will even package…More as well wrap any materials prior to delivering to the post office on time. The company extends its discounted rate on postage to its customers. Clients include local businesses, nonprofits and wineries. Services include direct ink-jet printing, machine and hand insertion and assembly, fliding and tabbing. Unique Mailing Systems has been locally owned and operated since its founding in 1987.