Entourage 2008 Autodiscover.xml and SSL Error

The Mac OS X operating system with Entourage 2008 messaging client may exhibit the following behaviour if the client Autodiscover lookup for https://domain.com/autodiscover/autodiscover.xml can be resolved, but is not an Exchange Server Autodiscover file.

Unable to establish a secure connection to domain.com because the correct root certificate is not installed



This seems to occur when the web server hosting https://domain.com/ has an untrusted or incorrect SSL certificate and the file https://domain.com/autodiscover/autodiscover.xml is accessible, but not in the correct format for Exchange Server Autodiscover.


The following solutions could be used to work around this:

· On the web server prevent resolution of https://domain.com/autodiscover/autodiscover.xml to a file.

· On the web server hosting https://domain.com/ install a valid SSL certificate from a public CA. Set a redirect on https://domain.com/autodiscover/autodiscover.xml to https://autodiscover.domain.com/autodiscover/autodiscover.xml hosted on the Exchange Server CAS role.


Where the above is not possible the following could be used:

· Set local hosts entry in the Mac OS X operating system for domain.com to resolve to (Note: this will prevent browsing to http://domain.com  from the computer)