Exchange 2003 to 2010 CAS migration work with public Certificate When you're upgrading your existing Microsoft Exchange Server 2003 organization to Exchange Server 2010, there's a period of time when both Exchange 2003 and Exchange 2010 will coexist within your organization. This topic describes the various steps you must take to upgrade an Exchange 2003 organization to Exchange 2010. After you've ensured that the prerequisites are met and you've obtained the correct certificates, you can begin your upgrade. Do this using the following steps. Note: In the following steps, replace <CAS2010> with the name of your Exchange 2010 Client Access server. Install the Exchange 2010 Client Access server role. During Setup, you can enter the primary external namespace for your virtual directories. This value should be the
