I'm trying to e mail a 70.3MB file video I need to know how to resize it to a 10MB can someone help me

You will probably need some software to accomplish this.

Here is a link to one, there are many available.

Resize Video (AVI, MPG, MPEG, WMV Files) Software

Depending on the Format of the video you may already ber at the max compression. What you may want to do is use:

YouSendIt - Send large files - transfer delivery - FTP Replacement

Scott's right. You don't want to blow away someone's InBox with even a 10mb attachment. Post your file on the net somewhere secure and send your recipient a link so they can download it at their leisure.