I am upgrading a Unity 4.03 install to Unity 7.x. There is one exchange 2003 server as the partner. The 7.x install will be on new hardware and I just need to migrate the users from one server to the other. My question is can I install the 7.x software and connect it to the Exchange server while Unity 4.x is still running on this Exchange server? And if so can I then just use GSM to migrate the users?