In Rhinebeck, NY - the home of American Postal Owners - the post office is USPS owned. Although it serves well over 10,000 people, the hours are being reduced from 8:30am-7pm to 9am-5pm. When purchasing post offices, people often strongly consider the hours of operation; however, this is clearly no longer a true indicator of a property's business.
Do not allow other associations to scare you into selling your existing properties at an unfair price or prevent you from investing in new properties. The closing and consolidations have to do with branch offices in large cities and large processing and distribution centers.
Keep this in mind if you are concerned about the USPS closing small rural post offices: under a federal law aimed at ensuring service for rural and remote areas, economizing cannot be the sole factor for closing a post office.