I wouldn't even try, Sam. Most ISPs have such limits.
Adding an attachment to a message increases the total size of the email by roughly 35%, so, e.g., a 10KB message with a 79MB attachment would become a 106MB email!
You could copy the video to CD and snail-mail that.
If you both use, e.g., MSN Messenger and are both logged in at the time, use File>Send a File. (Hopefully you have Verizon DSL!)