I work for a company that hosts a number of client domains within our
network. They use our DNS for all there name resolution needs.

What I want is to forward ALL requests to the internet, EXCEPT for those
resources that are on our local network. For instance say I am working with

If I am hosting their mail, I want the MX record for COMPANY.COM to resolve
to the internal address, but if their WWW server in on the internet
I want it to resolve to the public IP address by forwarding the request to
the Internet DNS server.

This was working until a week ago, it is not working right now! Nothing has
changed on this server since that time. (I have applied service packs to
other servers in the tree)

Any ideas

Thanks in advance