OK here is the scenario:

Friend has 2 email accounts in 2 separate places:

John@Here.com

Johnny@There.com (Here.com and THere.com are completely unrelated to each other)

I sent an email to John@There.com. Obviously that user doesn't exist in that email address.
So EXACTLY what happens?

See it is a rather sensitive email..and i don't want the administrator of There.com to see it.

I know there must be a way for the administrator for the pop mail server in There.com to see the nondeliverable message...but is it easy to view it?

My friend says that nondeliverable mails will be returned without anyone seeing it...
it'll usually say Postmaster@There.com sent me back the message. But the postmaster is like a bot right? It automatically sends it back. Can an administrator see the mail easily?

HELP...someone explain the basics of POP and SMTP to me please.....