DNS Resolving problem

[S. Zain]

I have Bind 8.3.7 and i have a problem that one of the Domains is resolved
in the two DNS's, the domain is (polaris.co.in).

    I am getting this massage:
            smtp.polaris.co.in
            Server:  ns1.MYISP.net.sa
            Address:  XXX.XXX.XXX.101
            *** ns1.MYISP.net.sa can't find smtp.polaris.co.in: Non-existent
host/domain

    If i try to Resolve the main Domain.
            polaris.co.in
            Server:  ns1.MYISP.net.sa
            Address:  XXX.XXX.XXX.101

            Non-authoritative answer:
                    polaris.co.in   preference = 1, mail exchanger =
smtp.polaris.co.in
                    polaris.co.in   preference = 3, mail exchanger =
rsmtp.polaris.co.in
                    polaris.co.in   preference = 2, mail exchanger =
psldns.polaris.co.in

                    Authoritative answers can be found from:
                    polaris.co.in   nameserver = dns1.polaris.co.in
                    polaris.co.in   nameserver = dns2.polaris.co.in
                    polaris.co.in   nameserver = dns3.polaris.co.in
                    smtp.polaris.co.in      internet address =
203.197.144.71
                    rsmtp.polaris.co.in     internet address =
203.196.190.68
                    psldns.polaris.co.in    internet address =
203.197.144.72
                    dns1.polaris.co.in      internet address =
203.197.144.66
                    dns2.polaris.co.in      internet address =
203.197.144.67
                    dns3.polaris.co.in      internet address = 202.54.218.7


What could be the problem.

Best Regards
Zain