Well the truth is ya cant – its best to have it resent by the sender but that usually doesn’t help. Its a setting in outlook that creates these strange and seemingly orphaned files – noting can open them simply or natively, but there is hope – today I stumbled across winmaildat.com. all you have to do is upload your file, 5mb maximum, and within a few seconds its right there in front of your face ready to be downloaded. This is a great relief for PC users who have to frequently download apps and install them without really knowing their origin.