Using forwarders results in mail server issue.

[Zelck, Guy]

Hello all,

Inside our company (eds.com) I manage our groups own little domain
(es.be.eds.com) with bind 8.2.3 on Solaris8.
We also have sendmail configured for our own domain on a different unix
server. This mail server handles mail send to domain es.be.eds.com and uses
the smart relay of EDS (defined in sendmail.cf) to deliver mail to other
domains. I also have an MX record in our zone file with only our local mail
server in it. So far so good, everything works.

Now I wanted to introduce in BIND a forwarder that knows all internet
addresses. This forwarder is one of the main EDS internet gateways. 
So I changed named.conf to have:
options {
#
# boot file for authoritive master name server for Berkeley.EDU
# Note that there should be one primary entry for each SOA record.
#
#
        directory "/var/named";
        notify yes;
        forward first;
        forwarders {
               199.42.132.115;
       };
}; 

For DNS resolving everything works as expected, internet hosts get resolved
fine along with the local addresses.
The problem is that sendmail doesn't deliver mail for eg guy at es.be.eds.com
anymore. It suddenly uses a relay it got, I suppose, from the foreign
forwarder i.s.o. relaying the mail itself. I get the feeling that if there
would have been an option like 'forwarders last' I wouldn't have this
problem. I know however that this option doesn't exist unfortunately.

How can we get round this problem? Anyone knows?

Thanks,
Guy.