I've never tried sending video in text, only email. It won't go through. If i'm on t-mobiles network it says the size is too large to send. So if i log onto wifi, it doesn't give me this notice, it seems to do it, but the person never gets my email.
So I don't know, prolly just have to call t-mobile and see if they can help. I dont send many videos so not a big deal to me right now.