Section 5253 Of Article 6. Proceedings From California Public Utilities Code >> Division 2. >> Chapter 7. >> Article 6.

. Service of all process and orders, decisions and orders, orders and notices in all such proceedings, investigations, complaints and hearings may be made personally or by the deposit in the United States mail of a sealed envelope with postage prepaid, containing a true copy of the paper to be served and addressed to the person to be served at his last known address as shown by the records of the commission.