I have just migrated a company using Windows XP from Novell. They used the Group-wise messenger and loved it. I have been asked to set up "A Windows Equivalent" to Group-wise, however, they want the Messenger to be restricted to internal addresses only. This is all connected to a Windows Small Business Server 2008 Domain. As The SBS creates firstname.lastname@example.org, is there a way to set up and use Windows Messenger on the internal network Only?