> The charge of robbery of any person having lawful charge, control or custody of any mail matter or of any money or other property of the United States provides for a sentence of up to 10 years in prison, at least three years of supervised release and a fine of up to $250,000.

Pro-tip, don't fuck with the postal service. Really quick way to get the federal law enforcement involved which both makes getting caught way more likely AND massively increase the consequences when you do.