I have an Exchange 2003 Server on Windows SBS 2003. Between my server and the internet is a DSL-504 D-Link router.
I have one user that refuses to connect to the network in any way but wants to POP email out of the exchange server. His computer is a laptop. When he is on the road and uses dial up internet, he can POP the mail out of the server (using mail.ourdomainname.com as the POP server. However when he is in the workshop (same network/subnet but not connected to the domain) he cannot receive mail on mail.ourdomainname.com and has to use the computer name or IP Address of the server to be able to get the mail. We are using ourdomainname.local for our internal domain.
We can obviously make it work by changing the POP server depending on whether he is internal/external to the local network, but It would be far better if he could collect his mail on mail.ourdomainname.com no matter where he is.