http://blogs.technet.com/b/omers/archive/2013/02/20/exchange-firewalls-and-support-oh-my.aspxOver the years Exchange Server architecture has gone through a number of changes. As a product matures over time you may see us change what is supported as we react to changes in the product architecture, the state of technology as a whole, or major supporten-USTelligent Evolution Platform Developer Build (Build: 5.6.50428.7875)