Article ID: 2735321 - View products that this article applies to.
Assume that you use Microsoft Lync Server 2010 Control Panel to set the global file transfer filter to Block all. In this situation, you can still send files that have a file name that uses a double-byte character set and that contains more than 8 characters.
To resolve the issue, install the following cumulative update:
(http://support.microsoft.com/kb/2737915/ )Description of the cumulative update for Lync Server 2010: October 2012
For more information about how to change the default file transfer filter, go to the following Microsoft website:
How to change the default file transfer filter