how to setup Exchange 2007 for Outlook Anywhere?

I am trying to configure Outlook Anywhere on MS Outlook 2003 and the backend server is Exchange 2007 server. The server has a Public IP (80.x.x.x)but no DNS (internet Ready)pointer yet diverted to it. I am trying to configure the client over the internet using the IP or domain but no go. I can however access OWA and also send emails to self but not to anyone else, either within the exchange directory database or outside. I am new to 2007 exchange looks like i am missing the steps to do this. Please help showing the right steps. thanks!