Microsoft released the updates required to allow Exchange 2013 to be introduced into existing Exchange 2007 and Exchange 2010 environments. Before the release of these updates, customers who had Exchange 2007 or Exchange 2010 couldn’t upgrade to Exchange 2013. Exchange 2013 could only be deployed in customers who didn’t have any prior version of Exchange. In this blog post, I walk-through the updates required for Exchange 2007 and Exchange 2010 to have Exchange 2013 introduced and then walkthrough the deployment of Exchange 2013.
Note: Coexistence with Exchange 2003 and Exchange 2013 is not supported. If you have Exchange 2003, then you will need to upgrade first to Exchange 2007 or 2010 and then upgrade to Exchange 2013
(Exchange 2013 has a new web-based admin console called the Exchange Admin Console. There is no Exchange MMC anymore)
The step by step build document is attached: Exchange 2013 Coexistence with Exchange 2007 and 2010