No access to some User's Calendar

[Caballero1]

Hello. Client using Outlook 2007 and can't access some of the other user's Calendar & apparently he's been given permission to do so. – I tested the Autodiscover on client's Outlook (by holding down CTRL and clicking on the Outlook client icon in the system tray), selecting 'Test Email Autoconfiguration', in the resulting window uncheck 'Use Guessmart', hit the Test button & it failed.

Without getting too complex, Microsoft.com informs that unlike Outlook 2003 and earlier versions (which uses Public folders for free busy as well),Outlook 2007 uses the new E2K7 Availability service (EWS) to lookup free/busy information & that when working this basically gives to live free/busy information from the other users in the org.

So that's the problem. I am not sure what exchange server we're using & perhaps some of these other users are in different Exchange systems even versions (2003, 2007, etc). Also, the location does not have a local DC/Global Catalog Server and Exchange; these systems are in same domain but in another physical location but we do have a link to them so we can authenticate, user Outlook via Mapi (not sure if anything after exchange 2003 uses that protocol within an domain/office).

Thanks!