Please make sure your Airport Express is not set to bridge mode as DNS changes will not work. Instead set DNS on your main router or remove bridge mode.
Open Airport Utility found in Applications > Utilities
Select the Airport Express from the menu and click edit
Select the Internet Tab
In DNS servers input Login to see and Login to see
Click update and wait for the Airport Express to restart
Restart the devices connected to the Airport Express that you want to use with dns4me
