I"m setting up a test organization with Exchange 2007. The domain name inside is divind.internal and the public domain is divind.com. I can connect to the Exchange server with Outlook 2007 no problem and send to anyone else using a divind.internal address. When I try to send an email out to the Internet, I get the following error:
Microsoft Exchange couldn't deliver the message to this recipient because it didn't recognize you as a valid sender. Please verify that you have the correct sending address configured in your e-mail client and try sending your message again, or provide the following diagnostic text to your system administrator
The following organization rejected your message: imta20.emeryville.ca.mail.comcast.net.
Now, I know that .internal is not routable over the Internet and .com is. How can I get this annoying error to go away?