Our nameservers do not respond with NS records. Best practice says they should, but I’ve never heard of this causing any problems.
Checking which nameservers are in use is a big more sophisticated than running a simple NS lookup query. A dig trace call works fairly well, which “Dig web interface” can do:
Our domain checker can also find nameservers pretty well.
Why are you asking about this at all? Did you notice it and were you wondering what it meant? Or are you experiencing any problems that you suspect may be caused by this?
The issue is that people using outlook can not send us emails. Microsoft error says aspmx.l.google.com. id not configured and and Google says its the NS is not working.
That seems to me like your DNS settings are fine, but Google’s mail servers do not have the email address configured. If the error references Google’s mail server, which it does, it means the DNS lookup is working.
Where does it say that? When you query for NS records with the dig interface? Because if so, you can ignore that, because NS records are not necessary and your domain will work fine without it.