DNS server will not resolve one server

[chazam]

Hello,

I have a Windows 2000 vpn server and Windows 2000 vpn client.
It is able to resolve all names of my servers except one.
I can ping the server by ip address and map drives by name but, I cannot ping by name.
I have tried it on an Win98 and XP machine and all works fine.
I have ran tracert on the servers that I can ping by name and it uses the VPN connection and my internal DNS servers.
But when I tracert to my mail server it will only use the DNS server provided by my ISP.
If I change the ISP's DNS server information to my internal DNS servers it works fine.

Any help would be greatly appreciated