Understanding Microsoft Exchange 2007 Coexistence with Exchange 2013
When Exchange 2013 will actually decide to proxy or redirect a request to a legacy Exchange 2007? Exchange 2013 will always try to proxy a request to other CAS 2013 servers or legacy versions, especially for Exchange 2010. The only exceptions are: Exchange 2007 OWA Exchange 2010 OWA or ECP /w ExternalURL set Workload Exchange 2007 Exchange 2010 OWA Redirect to ExternalURL (legacy namespace) Proxy Redirect if ExternalURL is set ECP N/A Proxy Redirect if ExternalURL is set POP/IMAP Proxy Proxy ActiveSync Proxy Proxy Autodiscover Proxy to Exchange 2013 MBX Proxy Outlook Anywhere Proxy Proxy Exchange Web Services (EWS) Autodiscover Req. (to retrieve the EWS 2007 URL and hand that to the user) Proxy Here's quick demonstration...