Question : When contacting <a rel="nofollow" href="https://mail.domain.com/autodiscover/autodiscover.xml" target="_blank">https://mail.domain.com/au<wbr />todiscover<wbr />/autodisco<wbr />ver.xml</a> receiv

I replaced the exchange 2007 self signed certificate with a commercial one and all services work fine.[ owa, Outlook Anywhere, active sync etc]. Modified all EWS services to use the new certificate as per the TechNet article http://support.microsoft.com/kb/940726 to fix the certificate warning error and Outlook 2007 works OK too.
Issue is when I use test-outlookwebservice cmdlet it gives the error  bellow.
Id      : 1013
Type    : Error
Message : When contacting https://access.siemens.com.au/autodiscover/autodiscover.xml received the  error The remote server returned an error: (401) Unauthorized.
If I change URIs back to server name it can contact the .xml file but get the certificate error. What is causing this?
Thanks , jayaj1

Answer : When contacting <a rel="nofollow" href="https://mail.domain.com/autodiscover/autodiscover.xml" target="_blank">https://mail.domain.com/au<wbr />todiscover<wbr />/autodisco<wbr />ver.xml</a> receiv

See the following:
http://www.exchange-genie.com/2007/07/401-error-when-attempting-test-outlookwebservices/
http://support.microsoft.com/?id=896861

It will always fail, unless you disable loopback checking (which should only be done for testing and re-enabled afterward)