Playing digital copy and other mp4?

[nhcress]

i've been going back and firth from thread to thread and cant seem to find exactly the answer i need. i have a couple of vids (sent via email) that i cannot seem to play on my phone. they are both mp4 format. i also just transfered a digital copy of a movie onto my phone, x-men origins: wolverine to be exact, and cant get it to play either. i transfered it into itunes, do i need to do it throught windows media player instead? i have a 2 month old droid x. any help would be greatly appreciated. i tried act one video player and it said it was a playable file but didnt work