Certainly good advice.
But if the courts decide that the Post Office cannot ban guns, I guess I'd like to see the reasoning that says courts ARE allowed to ban guns. I understand why they would want to, but it's obvious infringement and why is that OK here but not there?
Pretty simple under the Bruen decision. It was acceptable to ban guns in courtrooms (which usually had armed security in the form of a baliff), when the Second Amendment was ratified in 1791. There was no statute or history of banning guns in post offices until 1972.
The ban on guns in courtrooms was accepted as a legitimate restriction on the right to keep and bear arms at the time the Second Amendment was ratified. Bans on guns in post offices were not.