Sounds like those Chain Mail Letters from the 80’s................
Once they realized they were setting a lot of mail on fire rhe USPS stopped doing it. Congress directed them to do it. Surebeam leased the equipment and would be paid by the tons of mail irradiated.
Surebeam was a subsidiary of Titan Industries. They were irradiation sides of been, poultry, fresh fruits, by bombarding the whole trailer container with radiation.
I still expect that to roll out on pandemic mandates soon.
https://spectrum.ieee.org/update-surebeam-goes-under