Legal Question in Real Estate Law in California

Only the clerk of the court is permitted to serve small claims and orders to appear on a defendant, by using mail with return receipt requested. (Code of Civ. Proc., sect. 116.340.) A party serving must use personal service or substituted service.

As of right now, it sounds as though you do not have valid service. At the hearing when the defendant appears, the judge or judge pro tem will usually ask whether the defendant waives defective service. If the defendant does not waive defective service, the hearing will usually be postponed for at least 15 days.

You likely will see this response too late to help; you should have posted much earlier.

Normally, if a Defendant appears in court there is no need to show they were served; the purpose of service is to notify the party of the date and time to appear and to have time to prepare their case. If the party shows up, the purpose is fulfilled. Their answering the judge's question of whether they were served is sufficient to show they were. I suspect your question is really about something else.