Assume that you use Microsoft Lync Server Control Panel to set the global file transfer filter to Block all. In this situation, a Lync 2010 user can still send files that contain a file name of more than 58 characters.
To resolve this issue, install the following cumulative update:
2670352 Description of the cumulative update for Lync Server 2010: February 2012
For more information about how to change the global filter, visit the following Microsoft website: