Cal. CIV § 2924.3

(a) Except as provided in subdivisions (b) and (c), a person who has undertaken as an agent of a mortgagee, beneficiary, or owner of a promissory note secured directly or collaterally by a mortgage or deed of trust on real property or an estate for years therein, to make collections of payments from an obligor under the note, shall mail the following notices, postage prepaid, to each mortgagee, beneficiary or owner for whom the agent has agreed to make collections from the obligor under the note:

(1) A copy of the notice of default filed in the office of the county recorder pursuant to Section 2924 on account of a breach of obligation under the promissory note on which the agent has agreed to make collections of payments, within 15 days after recordation.

(2) Notice that a notice of default has been recorded pursuant to Section 2924 on account of a breach of an obligation secured by a mortgage or deed of trust against the same property or estate for years therein having priority over the mortgage or deed of trust securing the obligation described in paragraph (1), within 15 days after recordation or within three business days after the agent receives the information, whichever is later.

(3) Notice of the time and place scheduled for the sale of the real property or estate for years therein pursuant to Section 2924f under a power of sale in a mortgage or deed of trust securing an obligation described in paragraphs (1) or (2), not less than 15 days before the scheduled date of the sale or not later than the next business day after the agent receives the information, whichever is later.

(b) An agent who has undertaken to make collections on behalf of mortgagees, beneficiaries or owners of promissory notes secured by mortgages or deeds of trust on real property or an estate for years therein shall not be required to comply with the provisions of subdivision (a) with respect to a mortgagee, beneficiary or owner who is entitled to receive notice pursuant to subdivision (c) of Section 2924b or for whom a request for notice has been recorded pursuant to subdivision (b) of Section 2924b if the agent reasonably believes that the address of the mortgagee, beneficiary, or owner described in Section 2924b is the current business or residence address of that person.

(c) An agent who has undertaken to make collections on behalf of mortgagees, beneficiaries or owners of promissory notes secured by mortgages or deeds of trust on real property or an estate for years therein shall not be required to comply with the provisions of paragraph (1) or (2) of subdivision (a) if the agent knows or reasonably believes that the default has already been cured by or on behalf of the obligor.

(d) Any failure to comply with the provisions of this section shall not affect the validity of a sale in favor of a bona fide purchaser or the rights of an encumbrancer for value and without notice.