cant acces domains who are running in my box

Hi, I have a problem whit the susefirewall. My internal network cant access my webserver and pop and more. When i connect to the IP witch suse have (192.168.1.10) then there is no problem. When i try to connect to www.mydomain.com then i have a problem. This problem i have only whit domains who are running on my box. So i can access al the other interet pages. I have checked /etc/sysconfig/susefirewall2 but i cant find what i most set there to fix this problem. Greets Wouter P.S. sorry for my bad english.