In India postmen also can gauge the contents of the letter or document. For example, they can recognize US college acceptance letters for students trying for further studies. Many of them will then ask for gifts for delivering the good news.
That's not right at all. The people of the Soviet Union had the money through most of the country's history; however, they often couldn't easily exchange that money for useful, quality goods like food, kitchenware, furniture or cars [1] without the proper connections and bribery. Bribes were often (perhaps mostly) not payed in money, either.
[1] As opposed to less useful goods like political books with titles along the lines of "The Proceedings of the Nth Congress of the Communist Party of the Soviet Union", which were plenty, and which you sometimes had to buy by the dozen in order for the salesperson to agree to sell you a few more desirable books.