Company merged one of us a 30ish N shop with GW 2012 the other a 27 user MS shop with exchange 2003
We've (the other IT guy and I) decided to create everything new so we have new OES 11 sp 2 servers with a new tree.
We are installing GW 2014 - When the setup screen asks for the Host Name or IP address - Does it want the Internal IP address? or the External one? - We are using one to one Nat to translate our IP addresses. We don't have an internal DNS server, but will set one up if we need one. If needed I assume we will have to do that first before installing GW?

Other than that, we will need to decide what to do with both company's old email at some point because I'm sure many of the users will want their old email and contacts, etc. and many of them use their email as a **** file-cabnet, so any suggestions on that front would be welcome.