I was asked today about an Outlook synchronisation of the address book over the web (RPC over http) and did some digging and found this excellent diagnosis tool - https://www.testexchangeconnectivity.com.  The nice thing is that it tests many products – Exchange, ActiveSync and Office 365.

Once you start the tool you have to choose what diagnosis you want:

or

After you have completed your sign-in details, you get the results.  In the example below it shows that my certificate is not publically signed and a number of other issues that I could address if they were the cause of connectivity issues (but I don’t need to as I get the functionality I want with the current setup)

ttfn

David