I have installed Motioneye however although it does send snapshot pictures via email I cannot get it to send movies. I have tried various formats but none seem to work. All I get when I turn off snapshots is the notification Motioneye has detected motion in an empty email.
I would recommend to get in touch with the MotionEye project via their GitHub repository.
Apparently Motioneye is designed not to send movies via email.