Managed to start a support ticket with XenForo, explaining in some detail the email alert issues.The XenForo documentation is surely online. Why don't you do us all a favour, look it up, and let us know how it's supposed to work?
Thanks.
First response - You would need to have the forum owner contact us for support as we can not look into anything without their request.
Next asked if they could supply contact details for site owner.
Second response - Indeed it is a catch 22, as we likewise cant provide that information under our data protection obligations.
Done everything I can. Something as basic as knowing how email alert settings should work turns into a real hard if not impossible ask.