[SmoothOperator]

Oh, no! Isn't the carrier.blackberry.net address known for its high security? I understand that this address is dedicated to device only, thus a higher level of security.

Anyhow, I finally got the problem solved. The people at AT&T customer support couldn't solve the problem, but the fault was finally fixed after nearly two hours of troubleshooting from the people at the highest level of tech support at both AT&T and Blackberry in a conference call, and I mean talking to people directly involved with the software that runs Blackberry. It was quite baffling to everyone, because why could I send email, yet not receive from att.blackberry.net? The fault lies in my Blackberry ID, that the username is based on an obscure email service (email.com) that I have been using way back in the last millenium. The Blackberry server does not jive with that email account, so I had to change my username (options -> device -> Blackberry ID) to something more familiar (gmail) to the Blackberry system. After changing from email to gmail for my username, I could now set up my ATT.Blackberry.net account, and it now works. The fix took about maybe fifteen minutes, but identifying the problem took over 90 minutes. It took a while, but the problem is now fixed.