Hey, I'm Isaak, better known as Shiropoint on Youtube
and I'd happy to help with this in any way
I'm not sure whether sending the files in via email is for the best, not as attachment at least. Video files can get fairly big if you want to squeeze out enough quality. A great lossy format is for instance Quicktime with the animation or h264 codec but for a video of a few minutes that could mean several hundreds of megabytes. You could go with the mp4 format and h264 combo, but again this can mean dozens of megabytes.
So maybe the videos could be given via flashdrive, or perhaps they could be uploaded to a Dropbox or Google Drive?
Also, not every player can play every file. VLC player will play just about everything, but Windows Media Player won't accept some files without the appropriate codecs.
My two pennies