Yes the legal system in CA requires that at least one person other than the person being insulted here understands it is a defamatory statement made in writing

Yes the legal system in CA requires that at least one person other than the person being insulted here understands it is a defamatory statement made in writing for a a libel per quod case. It doesn't require the general public or a theoretical reasonable person would understand it, but then as a practical matter unless many who received the message understand it the damages would be minimal and it wouldn't be worth a civil case. And it still needs to meet all the other requirements, the statement needs to be provably false. Not just an opinion, not a substantially true statement, that the statements were made(in writing) to someone other than who they were about, there were actual damages and they damages were substantially caused by the libelous writing. Showing actual damages in a defamation case is hard