mardoch

So the problem came from a blank field in the settings.
For some server (verizon), the “Send From Email:” field is required, so don’t leave it blank or it will fail

Yes, I did it as I said. I test it with 2 difderents emails adresses to be sure that the problem isn’t coming from mailbox but I never received any mail from the test mail. Even if it noticed this: “the wp_mail function signaled success.”