California Code, Civil Code - CIV § 798.42

(b)(1) Upon voluntary, written consent of a homeowner or resident, the management may provide notice under this section by electronic communication in a form of electronic communication to which the homeowner or resident consents.

(2) For each homeowner or resident not provided notice by electronic communication, the management shall post written notice on the mobilehome of the affected homeowner or resident.

(1) “Electronic communication” means email, text, or automated telephone call.

(2) “Emergency” means the interruption of utility service resulting from an accident or act of nature, or cessation of service caused by other than the management's regular or planned maintenance, repair, or replacement of utility facilities.

(3) “Voluntary, written consent” means written consent obtained separately from, and not contained in, any lease or rental agreement.  Voluntary consent may be revoked by the homeowner or resident in writing at any time.