Where is the smallest U.S. Post Office?

Smallest Post Office in the United States

From the article: "...Ochopee, Florida -This closet-sized, 7x8-foot building used to be an irrigation pipe shed for a tomato farm. It was pressed into service after a fire destroyed the Ochopee general store..."

Article Reference: www.roadsideamerica.com
Where is the smallest U.S. Post Office?, Smallest Post Office, 34141-9998,