I am using Media 100 version 8.2.1. I'm exporting my 640 by 480 project to 320 by 240 MPEG4's just fine. When I select MPEG-4 from the Export To sub menu, I get my options but no file extension. I can open up my files in QT just fine. What I'm concerned about is emailing these smaller files and the client not able to open them up. Are they XYZ.MPG4 ??? or ABC.MPEG-4 ???