Wyo. Stat. § 20-6-203: Notices; method of service.

All notices required by this act shall be served by certified mail return receipt requested or first class mail to the last known address of the addressee or shall be personally served as provided by the Wyoming Rules of Civil Procedure. If mailed, notice shall be deemed given when deposited in the United States mail, postage prepaid. Proof of mailing shall be sufficient proof of notice.