To require viewers to submit their email address in order to view your online hosted video, (known as email capture, or email gating) go to your Videos tab, and open one of your videos.
Once you are on the video details page, scroll down and check the box next to ‘Require email to watch video’ then click ‘Save Changes’:
Now, before a viewer enters their email address, your video will be displayed like this:
Custom Email Capture Message
If you are embedding your video you can customize the email capture message.
Check out these other articles in the Playing Videos section: