We recently upgraded our DSL service. In doing so, we have a "new" static (public) IP address. We use BellSouth as our service provider (which is PPOE); therefore, the only change to get Internet working was to change the User ID and Password in the Dlink DSL router (Alcatel Speed Touch Home DSL modem) is connected to Dlink router) that we use. Dlink router is attached to external NIC on our SBS 2003 server.
We host our own Exchange Server as part of SBS 2003. I accessed our internet domain host account (we use BellSouth Web Hosting) and changed the MX record to the new IP address. After a few minutes, I checked to see if the change was effective at DNSStuff.com. Indeed the MX record contained the new Static IP address. We also use MailHop Backup MX from Dyndns.com.
I made no changes to SBS 2003.
After making the changes, I tried sending an email to our Exchange Server and the message was "bounced" back.
Do I have to make a change to some element of SBS 2003 for it to recognize the new public IP address? We also use OWA to access our email remotely.