We have a dedicated SPAM filter running Linux Debian (Etch) implementing Postfix/Amavis/SA/Clamd. Amavis-new is blocking new MS Office 2007 with messages similar to the following:
X-Amavis-Alert: BANNED, message contains part: multipart/mixed | application/octet-stream,.zip
My company has asked me to allow docx / xlsx / pptx fomats as attachments. How should I do this without opening a huge security hole?