Jerry Stuckle wrote:

> You are not relaying them, then. You are acting as their mail MTA.

That's what MTA's do - they relay mail.
You can't be an MTA without relaying mail.
If you do - you're a POP.

> And NorTel's intranet servers are not publicly available. Nor are
> GTE's. I don't know about your clients.

That depends on your defintion of "publicly available".