Anonymous or threatening letters, mailing or transmitting

It shall be unlawful for any person, firm, or corporation, or any association of persons in this State, under whatever name styled, to write and transmit any letter, note, or writing, whether written, printed, or drawn, without signing his, her, their, or its true name thereto, threatening any person or persons, firm or corporation, or officers thereof with any personal injury or violence or destruction of property of such individuals, firms, or corporations, or using therein any language or threats of any kind or nature calculated to intimidate or place in fear any such persons, firms or corporations, or officers thereof, as to their personal safety or the safety of their property, or using vulgar or obscene language, or using such language which if published would bring such persons into public contempt and disgrace, and any person, firm, or corporation violating the provisions of this section shall be guilty of a Class 1 misdemeanor.