Outlook 2007 / 2010 SSL warning

Even though you have forked out on a verified SSL cert, internal Outlook 2007/2010 clients get this warning when opening Outlook.

This is because the CAS is using the internal DNS name rather than the external name. For example https://mail.domail.local/ rather than https://mail.domain.com/

Set-WebServicesVirtualDirectory -Identity "CAS_Server_Name\EWS (Default Web Site)" -InternalUrl https://mail.contoso.com/ews/exchange.asmx

Set-OABVirtualDirectory -Identity "CAS_Server_name\oab (Default Web Site)" -InternalUrl https://mail.contoso.com/oab

Set-ClientAccessServer -Identity CAS_Server_Name -AutodiscoverServiceInternalUri https://mail.contoso.com/autodiscover/autodiscover.xml

See http://support.microsoft.com/kb/940726 for more info