How do I compress an MP4 so I can email it

I seem to be having difficulty.
I had an option to compress which zipped my file from 20mb to 19mb which means I guess I was doing something wrong!
Now I can't even find that option any more which is very weird.
I've tried doing it through iphoto without success and I've also downloaded to my desktop and tried through quicktime but can't find an option.
Any help gratefully received.

Aha. To add to that, when I look at the file in finder there's an option in 'file' which says 'compress xxx xxxxx'. That was the option which only compressed it by one mb.
Thanks again for any help.

How long is the .mp4? Compressing the file to something that is a manageable e-mail size is likely to adversely affect the quality significantly. Many e-mail gateways limit the size of attached files. The best option might be to post it somewhere and then e-mail the link to anyone you want to see it.

It's 20mb. About a minute and a half.
I thought that I could zip it to a manageable size but I have no idea how to.

This has been asked and answered here a hundred times before, but in summary: emailing videos longer than 30 seconds is a BAD IDEA, especially if the recipient doesn't know it's coming.

Post the video to the web somewhere, mark it "private" and email the URL (and password if needed) to the recipient. If you're a MobileMe or Dropbox member, post it there and notify them of how to download it.

Much better approach.