In the March 2018 update for Lync2013/SfB2015 and SfB2016 a new setting was included that can disable file upload to external conferences (Federated and Anonymous). Before this update the Lync/SfB Client didn't had a setting that could prevent file upload to external meetings: We can configure the EnableExternalFileTransferInConference setting with Inband Policy or Register Key: Inband Policy $a … Continue reading Lync/SfB Client: Disable file upload to external conferences →