On May 9 Microsoft® distributed a patch for Exchange Server 2000 and 2003 via its Windows Update service that could affect users of Lucatec® Mask. Before that patch all users with the “Full mailbox access” privilege implicitly had the “Send As” privilege as well. Now you have to grant this right explicitly. More details and a script for automating this are available from the Knowledge Base article describing the change which is linked below.