Exchange 2013 ECP/OWA/Outlook all failing - 503 Service Unavailable
No thanks to the helpful down voters. The nice people at Experts Exchange helped out.
The solution was the SSL certificate seemed to have come off of the Exchange Backend website. Selected the Exchange certificate on the IIS site and it started working. for all the details please see http://www.experts-exchange.com/questions/28699498/Exchange-2013-ECP-OWA-Outlook-all-failing-503-Service-Unavailable.html