You are the messaging engineer for your company. Your company has Microsoft Office Outlook 2007 licenses for all client computers. You plan to deploy Exchange Server 2007. You need to prevent client computers that run earlier versions of Outlook from connecting to your Exchange Server 2007 servers. What should you do?

A.
Use the Exchange Management Console to disable the MAPI feature for all mailboxes.

B.
Use the Exchange Management Console to assign a managed folder mailbox policy.

C.
Import the 2007 Office System Administrative Templates into the Default Domain Group Policy Object.

D.
Use the Exchange Management Shell to run the Set-CASMailbox cmdlet.

Explanation:
Use the EM Shell to establish client blocking by Outlook version on a per-mailbox basis. To block access by Outlook clients prior to a certain version number, run:

Set-CASMailbox -Identity <mailbox SMTP address> -MAPIBlockOutlookVersions: <version number>

To block access to all mailboxes on a particular server, you must use the Registry Editor: Set the following registry subkey (DWORD Value) to block the desired versions of Outlook (for example, 0.0.0-5.9.9; 7.0.0-):

HKLMSystemCurrentControlSetServicesMSExchangeISParametersSystemDisable MAPI

Clients

Restart the Information Store Service to make the change effective immediately.

http://technet.microsoft.com/en-us/library/bb885056.aspx

http://support.microsoft.com/?id=288894

Use Office 2007 System Administrative Templates to define and maintain an office configuration on client computers. Unlike other customization — for example, default values distributed in a Setup file — GPO settings are periodically re-enforced and can thus be used to determine a closely managed environment.

http://technet2.microsoft.com/Office/en-us/library/873a5392-1b1a-47a1-a863-1f29ef116d0e1033.mspx?mfr=true