FYI-NOT a VIP, and cant receive it. Sorry

How can you tell you have a private message if you're not a VIP? (Not being a smart ass,just curious.)

otherwise it is a mystery how he could know

If you are a regestered member you have to have an email address, so therefore TER can email you just in case you dont log in everyday on TER. Does that kind of explain things. I got a email from TER saying I had PRIVATE MAIL.

You can set your profile to email you when you have a PM.   Even though you cannot read the PM via email it will still notify you.  Every time I let my VIP expire, I get a PM and it drives me fucking crazy not to know who or what it is.... so I renew.  Great marketing tool to drive renewals.