Help with forwarders

[Steve Best]

I have setup bind-8.2.23p1 on a box running Red Hat 7.0.  This is a
DNS I have setup for out internal use, and so far has worked
correctly.  However, our email is offsite, as is our DNS, both of which
are hosted by XO.  I would like to have any queries for any addresses
hosted by XO's DNS servers to be served up by my internal DNS, especially
for smtp and pop3 requests.  I tried setting up a forwarders entry in
named.conf, and I still get an error when trying to do a lookup on
smtp and pop3.  This is also interferrng with our Bugzilla setup, since it
cannot email users their passwords after account creation.

Heres my named.conf:

options {
        directory "/var/named";
        forwarders {
                207.155.183.72;
        };
};

zone "bluetiger.com" in {
        type master;
        file "db.bluetiger.com";
};

zone "0.168.192.in-addr.arpa" in {
        type master;
        file "db.192.168.0";
};

zone "." in {
        type hint;
        file "named.root";
};

zone "0.0.127.in-addr.arpa" in {
        type master;
        file "db.127.0.0";
};

I also tried putting the forwarders entry in the db.bluetiger.com zone
entry, without success.  I am not even sure if forwarders will do what I
want.

Steve