Legal Question in Family Law in California

yes if it does everything required under Cal Civ proc sec 1005-1013.

If they are the initial papers in the case, no. If the case is already pending but the other parent has not filed responsive papers, no. Only if the case is already pending and the other parent has filed papers that constitute a general appearance, and they do not have an attorney, can you thereafter serve them by mail. If they have made a general appearance and have an attorney, you have to serve the attorney if you serve by mail.