Cal. Health & Safety Code § 15

Unless expressly otherwise provided, any notice required to be given to any person by any provision of this code may be given by mailing notice, postage prepaid, addressed to the person to be notified, at his residence or principal place of business in this State. The affidavit of the person who mails the notice, stating the facts of such mailing, is prima facie evidence that the notice was thus mailed.