There's long been a problem with Outlook, which rather than using standard attachment syntax, uses something called winmail.dat. It's another example of Microsoft intentionally not playing well with others. In the past, if a student has sent me a winmail.dat attachment, I've simply told the student to try again with something not Microsoft-proprietary.
I got a winmail.dat this morning from a co-worker, and rather than just say "try again," I decided to spend a few minutes on the problem (or pointy-haired opportunity). There's a site that seems to do a good job of extracting files from winmail.dat files: http://tud.at/php/tndef/index.php.
There are privacy issues here. Should one send personal, or work-related, or student-generated content to a third-party web site?