Different email providers have different limits on the sizes of attachments, so you
might find a provider offering to accept greater than 16Mb. (Even so, 16Mb is at the upper end of the usual limits. Some services don't allow more than 5Mb).
The usual way to send large files is to upload them to a file hosting service and then email a link to the recipient, so that they can download the file.
This file-hosting service is often recommended:
http://www.sendspace.com/
Here are a few alternatives:
http://www.yousendit.com/
http://www.transferbigfiles.com/
http://www.largefilesasap.com/
Chris