California Code, Health and Safety Code - HSC § 17958.3

(a) All residential hotels, as defined by paragraph (1) of subdivision (b) of Section 50519, shall provide a locking mail receptacle for each residential unit, consistent with the applicable standards for apartment housing mail receptacles in the United States Postal Service Domestic Mail Manual. Installation and maintenance of each mail receptacle shall meet all of the specifications and requirements of the United States Postal Service.

(b) Notwithstanding the date of construction of the residential hotel, each mail receptacle shall comply with the requirements of the Fair Housing Act (42 U.S.C. Sec. 3601).

(c) Notwithstanding Sections 17922, 17958, and 17958.5, a city, county, or city and county may enact and enforce ordinances which provide greater protections, additional standards, and increased remedies with respect to the provision of a locking mail receptacle for each residential unit in a residential hotel.

(d) This section shall become operative on July 1, 2008.