Outlook 2007 prompting for authentication after migrating to Exchange 2010

Client had an issue after I migrated them from Exchange 2007 to Exchange 2010 where users on Outlook 2007 were being prompted for authentication. Mail flow would work for the user but they were being prompted for authentication from the autodiscover url.

The fix for the was as follows

 

Set-ClientAccessServer -Identity CASSERVER -AutodiscoverServiceInternalUrihttps://url.domain.com/autodiscover/autodiscover.xml
Set-WebServicesVirtualDirectory -Identity " CASSERVER \EWS (Default Web Site)" -InternalUrl https://url.domain.com/ews/exchange.asmx
Set-OABVirtualDirectory -Identity " CASSERVER \oab (Default Web Site)" -InternalUrl https://url.domain.com/oab
Set-UMVirtualDirectory -Identity " CASSERVER \unifiedmessaging (Default Web Site)" -InternalUrl https://url.domain.com/unifiedmessaging/service.asmx

 

The final thing to do is to make sure if you are using a proxy server make sure there is an exception in the proxy list for the url of the autodiscover service