OK my first time so here we go. I've just migrated from Exchange 2003 to 2010. Everything internally is currently working with no issues. Problem is when i go to setup a account externally on outlook or mobile device it can not locate the server with the external name record. For example my FQDN internally ad.bluescafe.local can resolve users my external mx record name mx1.bluescafe.com can not. The setup is A Hostname mx1.bluescafe.local (208.223.xx.123)on the domain server then the Exchange server 192.168.x.x0 to firewall 1:1 Nat 208.223.xx.123 to godaddy mx1 record points to Nat 208.223.xx.123. Port25 is open on the firewall to allow SMTP-IN traffic from any external to Nat 208 and SMTP-out 192-168.x.x0 to any external out. I have tested port 25 from outside Telnet mx1.bluescafe.com 25 and it works but when i use that to configure out look or mobile device it fails to connect to server.