Hi,
You can send an iMovie project video via email by choosing the Email option from the share (export) menu.
Email providers limit the size of a video file that can be sent, so you may need to reduce the size of the video if the one that you want to send is too big. You can adjust the size from the resolutions settings in the email share box.
You can send an exported iMovie video by email, with the same size limitation caveats as mentioned above. You would open an email and drag in the movie.
Either method works fine, but emailing directly from the iMovie app gives you the size options, so I would go with that one.
You can also upload your video to You Tube and email the link to your video. You probably could do that with other video websites as well.
-- Rich