A.R.S. § 13-3004

A person who knowingly sends or delivers to another a letter or writing, whether subscribed or not, threatening to accuse him or another of a crime, or to expose or publish his failings or infirmities, and a writer or sender of an anonymous letter or writing calculated to create distrust of another or tending to impute dishonesty, want of chastity, drunkenness or any crime or infirmity to the receiver of the letter or to any other person, is guilty of a class 2 misdemeanor.