The sorting machines themselves are certainly not, but the general infrastructure around them sure can be. The World's Most Mechanized Post Office video [1] was

The sorting machines themselves are certainly not, but the general infrastructure around them sure can be. The World's Most Mechanized Post Office video [1] was filmed circa 1959 and it shows a crazy level of industrialization in the DC facility. Conveyor belts were invented in 1901 or so and such systems can run for a very long time with proper maintenance - for centuries even, replacing everything but the frame. Given how slowly government usually moves, they must have built up to that scale over decades. [1] https://www.youtube.com/watch?v=MuvwoBb7gs4 https://www.youtube.com/watch?v=MuvwoBb7gs4