lookup problem in dns

[Ron Croonenberg]

Ok, I'm not a real expert, but been around.

At my work we host a bunch of domains and one is giving e trouble.

when I look up the domain I get an answer from our nameserver and
everything seems to be ok. however when someone outside our domain wants
to lookup the domain. all nameservers (except ours) say that domain
doesn't exist.

If not mistaken, when a search for a domain is done and you own server
doesn't have the info, it asks for it from a root-server...correct ?

So does that mean if we can find it within our network, but nobody
outside can ...it might be the domain isn't in the rootserver anymore. ?

How can I see in a root domain server if it is registered there ?

I don't know for sure, but I have the impression that the domain I'm
looking for doesn't exist anymore. However how can I confirm that ?
(it's still in the WHOIS database.)

I know I might sound chaotic, but that what you get when you take over
someone else's undocumented stuff.

TIA,

Ron