I guess I can delete my post from January 2014 about it being legal to carry firearms onto Post Office property. Looks like back in June of 2015 the 10th Circuit Court of Appeals has reversed a 2013 ruling by District Judge Richard Matsch, saying, "The security of the postal building itself is integrally related to the security of the parking lot adjacent to it.”
In March 2016, the US Supreme Court refused to hear the Bonidy appeal, thus upholding the Circuit Court’s reversal. So, if you carry on a daily basis and have to go to the Post Office, you must park OFF Post Office property, leave your weapon in the car. Maybe it won’t get stolen. Maybe you won’t need it. Maybe you’ll go to UPS instead.
Oh, and by the way, the price of stamps just went down to $0.47. Stock up on Forever stamps, this won’t last long. The Post Office needs 180,000 new delivery trucks.