I have been satisfied with using the U.S. Post Office for shipping of numerous Green River Whiskey collectibles. Primarily, I have had absolutely no problem with insurance claims, while UPS is much slower to settle claims (one UPS claim took nearly two years to settle). On one other occasion, an article arrived broken. It took several months before UPS settled the claim. On top of that, even though there is a large UPS shipping station right here in my hometown, I had to go to another office 35 miles away. A young man took a chance on buying a Green River item for me from an antique shop in Kentucky some years ago (a very kind gesture as he didn't know me). I sent him a check with enough to pay for shipping. He shipped by UPS. Upon arrival, I discovered that the old cardboard game board had broken into two pieces. He did finally get paid for his claim, but they hassled him. I think you get my point about UPS.
But will the U.S. Post Office ship liquor? Yes, but with special restrictions. However, I have scores of bottles, several of which contain the original contents. To the best of my knowledge they were sent through the post office. I don't recall receiving anything through FedEx, however.
One other thing -- I'm not sure UPS has been totally to blame for the broken items. I have received hundreds of collectibles over the years, and it is only by the grace of God that some of them were not broken upon arrival. Very poor packing accounts for much of this. It shows that many sellers on eBay, etc., are good at hunting down exceptionally desirable material at estate and yard sales, flea markets and the like. They may be good at finding collectibles, but far too many have NO idea how little care is given to fragile items during shipping.
Sending or receiving collectible items requires great thought and care to ensure items arrive undamaged.