Business Insider reports on how the Allies during World War II got the Nazi postal service to deliver their propaganda for them. After bombing a German mail train near the city of Linz, Austria on Feb. 5, 1945, Allied aircraft dropped eight bags of mail among the wreckage.
"Inside each bag were 800 propaganda letters, all addressed to homes and businesses along the train’s route and appropriately stamped. When the train was discovered, German postal workers recovered the bags and delivered the letters without being any wiser about their contents or origins," writes Matt Soniak.
According to the article, "Operation Cornflakes (named so because the subversive mail was usually delivered just as its targets sat down for breakfast) had many advantages over simple airdrops, but required a lot of legwork to get off the ground. The inner workings of the German mail system had to be learned, so POWs who had been postal workers were interrogated about everything from postal cancellation markings to the ways mail bags were supposed to be packed and sealed. Spies and sympathizers gathered samples of stamps, postal cancellations, mail sacks, and envelopes while OSS staff pulled names and addresses from German telephone directories."
It goes on to say, "Every aspect of the German postal system, down to the smallest details, were replicated, with some small changes. Forgers manipulated the standard stamp with Adolf Hitler’s face to show the Fuhrer’s exposed skull. Other stamps had their country tag on the bottom changed from 'Deutsches Reich' (German Empire) to 'Futsches Reich' (Ruined Empire).