A summons may be served on a person outside this state in any manner provided by this article or by sending a copy of the summons and of the complaint to the person to be served by first-class mail, postage prepaid, requiring a return receipt. Service of a summons by this form of mail is deemed complete on the 10th day after such mailing.
Section 415.40
Code Civ. Proc. § 415.40 — under California Code Civ. Proc..
Code Civ. Proc. § 415.40