Mailing Threatening Communications 18 U.S.C. Sec. 876(d) is a criminal offense that involves sending a message of a threatening nature through the mail. The law applies to any communication that includes a threat to injure the recipient or to damage the recipient’s property. This includes threats of death, bodily harm, kidnapping, extortion, destruction of property, or any other threat that could put the recipient in danger or cause them to suffer financial harm. The law also applies to threats made against members of the recipient’s family, friends, or associates. The types of Mailing Threatening Communications 18 U.S.C. Sec. 876(d) can include letters, emails, postcards, or any other form of written communication sent through the mail.