Upon the filing of a complaint, the commission shall cause a copy thereof to be served upon the corporation, or person complained of. Service in all hearings, investigation and proceedings pending before the commission may be made upon any person upon whom a summons may be served in accordance with the provisions of the Code of Civil Procedure of this state, and may be made personally or by mailing in a sealed envelope, registered, with postage prepaid.
Idaho Code § 61-615