[cobalt-users] DNS Problem

["Masset bvba" <info@xxxxxxxxxxxx>]

Dear,

Today someone helped me with a dns problem (not a cobalt user member)
We want to use the raq2 server for dns .

I have setup the domein and forwarded the ip to another server
works fine
also the domain without the www. to ip
works fine

Now we run a mail server on NT

When I send mail to name@xxxxxxxxxxxxxxx it works fine
When I send mail to name@xxxxxxxxxxx it works fine i get this error

<sales@xxxxxxxxxxx>: Name service error for domain pop.nt4host.com: Host not
    found

The person who helped me put somewhere pop.nt4host.com is the files
I can not find it, so the problem keeps coming
Where could this be changed ? He tells me that he did not changed anything
So I think the christmas men did it

Please help

Steven