Can't Access External Domain Name From Inside Network

Can you confirm that your external domain name is different than your internal domain name?

If your internal domain name is the same as your external domain name you might have to configure a split DNS.

http://www.isaserver.org/tutorials/You_Need_to_Create_a_Split_DNS.html

The internal domain is the same as the external. I looked at the split dns, but cannot create the same zones on the internal server unliess I'm missing something?

If you internal DNS does not have an IP address for your webserver your clients won't know how to get there.

Add an entry to your DNS that points to the IP address of your webserver.

Do you host your website on a server on your internal network? If yes you will need to use the internal IP address of the web server because your firewall may not allow webtraffic out to the internet and back in.

The website is hosted externally. So, I add a forwarder or and A record to point to webser DNS?

Yes I would add an A record pointing to the internet IP address of your website.

If the web server is www.abc.com and its public IP is 10.11.12.13 then you would add an A record to your internal forward DNS zone abc.com for the host www, with that IP 10.11.12.13.

Just to try and understand...

Forward Look Up Zone:
  www.adc.com
      A x.x.x.x (internal server IP address)
      A x.x.x.x (internal server IP address)
      A x.x.x.x (exertnal IP address of website)

This is so weird...so I do an IP lookup on the web site www.seadwelling.com and get  98.129.229.14, but when you slap that into a web browser you dont get the website, so I can't make an A record for that.