For the past 18 months I have been using
You send it. This service will allow you to upload your file to their server where is will remain for x days or y downloads, and you send a download link.
The whole procedure is simplified by installing the you send it plugin for outlook, with this installed you compose you email and attach the file in the normal way then when you send the email the plug in asks if you want to send it via you send it or not.
