As you may already know, with Exchange 2010, Microsoft proposed an online tool to check the configuration of the remote connectivity configuration (Outlook Anywhere, Active Sync, Autodiscover…) – https://www.testexchangeconnectivity.com/

With the coming Office 365 and Exchange Online 2010, this tool will be updated to include specific function from Office 365, such as Single Sign On.

You can already try this at https://exrcastg.hughesonline.us/; please note that a certificate error may appears.