Local post offices were once considered illegal in the U.S. because they competed with the United States Post Office. But in 1952 Herman Herst of Scrub Oak, New York discovered a loophole in the private express status. The loophole permits a local post office to receive or distribute properly stamped mail which has traveled through regular U.S. Post Office channels. The local post stamps are stuck on the envelopes on the left hand side with the U.S. stamps in their usual place.
- Cadillac (New Jersey)
- Cheviot (Ohio)
- Czyl's Penny Post (Illinois)
- Deans Private (New York)
- Fireside
- FMF (Florida)
- HN (Illinois)
- Old Lighthouse (Delaware)