Ottawa County Sheriff Bob Bratton says the letter was returned to the Port Clinton jail where corrections officers read it along with the other incoming mail.
Donald Dudrow III of Toledo was indicted Thursday on charges of attempted drug trafficking and trying to get drugs into a correctional facility.
He already was in jail on a probation violation.
Jail officials didn't know whether Dudrow has an attorney.
Information from: Portsmouth Daily Times, http://www.portsmouth-dailytimes.com