Sendmail and DNS???

[alvin]

Hello,

I've setup my e-mail server(Redhat 6.0 & sendmail) recently, but got
some problem that  need someone help.........

All user within the domain can send e-mail to the outside world.
while someone on the outside world sending e-mail to my domain, the
e-mail returned with the error message " name server time out......"
I've  test my DNS configuration with NSLOOKUP and make sure that work
for outside world...
What's wrong ,Please help..

Alvin