Cal. Civ. Code § 55.1-1202

A. If the rental agreement so provides, the landlord and tenant may send notices in electronic form; however, any tenant who so requests may elect to send and receive notices in paper form. If electronic delivery is used, the sender shall retain sufficient proof of the electronic delivery, which may be an electronic receipt of delivery, a confirmation that the notice was sent by facsimile, or a certificate of service prepared by the sender confirming the electronic delivery.
B. In the case of the landlord, notice is served on the landlord at his place of business where the rental agreement was made or at any place held out by the landlord as the place for receipt of the communication.
In the case of the tenant, notice is served at the tenant's last known place of residence, which may be the dwelling unit.
C. Notice, knowledge, or a notice or notification received by an organization is effective for a particular transaction from the time it is brought to the attention of the person conducting that transaction, or from the time it would have been brought to his attention if the organization had exercised reasonable diligence.
D. No notice of termination of tenancy served upon a tenant by a public housing authority organized under the Housing Authorities Law (§ 36-1 et seq.) shall be effective unless it contains on its first page, in type no smaller or less legible than that otherwise used in the body of the notice, the name, address, and telephone number of the legal aid program, if any, serving the jurisdiction in which the premises is located.
No notice of termination of tenancy served upon a tenant receiving tenant-based rental assistance through (i) the Housing Choice Voucher Program, 42 U.S.C. § 1437f(o), or (ii) any other federal, state, or local program by a private landlord shall be effective unless it contains on its first page, in type no smaller or less legible than that otherwise used in the body of the notice, the statewide legal aid telephone number and website address.
E. The landlord may, in accordance with a written agreement, delegate to a managing agent or other third party the responsibility of providing any written notice under this chapter. The landlord may also engage an attorney at law to prepare or provide any written notice under this chapter or legal process under Title 8.01. Nothing herein shall be construed to preclude use of an electronic signature as defined in § 59.1-480 , or an electronic notarization as defined in § 47.1-2 , in any written notice under this chapter or legal process under Title 8.01.