You configure endpoint download policies for Microsoft Forefront Unified Access Gateway 2010 Service Pack 1 Client Application. If you configure the Identify by extension download policy, attachment files that have the extension that you specified are not blocked for download to the client.
To resolve this problem, install the service pack that is described in the following Microsoft Knowledge Base article:
2710791 Description of Service Pack 2 for Forefront Unified Access Gateway 2010
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about endpoint policies, visit the following Microsoft TechNet website: