Why servers can't launch netscape and red hat network?

Hi:
I have two servers ( MTA and FTP server ) and are redhat 7.2. I use a
workstation with redhat 7.2 as well. Both of server and workstation
install netscape browser.

The netscape browser and Red Hat Network Agent of workstation work ok. I
can launch them very fast so I can go into internet and use up2date to
upgrade my system.

My two servers can't launch netscape browser to internet and can't
launch Red Hat Network also! When I try to launch them, I got a red hat
nescape window then I get a error message ' the server refuse to
connects......' when I try to go to any webset.

Why and how should I do? PLS. help me!

Walter