Does such a thing exist?

I work at a community college that uses one name space. The problem is
that we have internally NAT'd devices on multiple NAT ranges as well as
EXTERNAL devices. The problem that I have is this.

I have 1 internal DNS server running on Netware that does NOT talk to
our external DNS server. The internal DNS server seems to believe that
it is the SOLE authoritative source for the entire name space but it isn't.

We need for it to look to our external DNS source even for things that
are in the same domain rather than to fail to resolve. As a work around
that seemed to work more or less until now was to create records for the
external devices. What has started happening though, is that mail being
sent by our instructors to our students (who have Google college e-mail
accounts) is failing to resolve an MX record for the mail (error 450).
Groupwise is only failing to send messages to our google addresses. We
can send TO our google addresses easily from other sources (home
accounts and the like) so we know that the google destination isn't DOWN.

I have set the Forwarding List to show our external DNS server and I'm
simply just not knowledgeable enough about DNS to really sort this all out.

Any help would be greatly appreciated.