One of our PCs is running W2000 Pro and Office 2000. We have an Exchange 5.5 server, though Internet email is processed by our ISP. This machine is on our LAN with a (10.0.0.xx) private address (like all of our others). This machine can send and receive intraoffice email no problem and can receive (only) Internet email, but anything that is SENT out to the Internet returns the following error:

"No transport provider was available for delivery to this recipient."

I have read pages and pages of stuff on support.microsoft.com about this, did everything I could find that they suggest to try to resolve this. I've uninstalled/reinstalled office twice. This machine is setup like the other 12 as best I can see, but the problem persists. It is making me nuts! Anyone have any suggestions???