In this video from whenwillapple we learn how to copy and paste video files on your iPhone. First go into your camera roll. Click on the thumbnail of the video file you would like to open. Once opened, tap and hold your finger on the screen until copy pops up on the screen. Tap the word copy. Now go to the home screen. Go into your mail and create a message. Tap and hold the blank area in the message until the paste options come up. Tap on the word paste and your file will paste into the email. If they are too large, usually more than a minute, it won't paste in email.