How can I email a PDF to a person from a website and track it?

This question was posed to me by a coworker. He just got this website that is pretty turn key, but he's working on some customization. The scenario is like this. A representative is face to face with a client. That rep has to talk to the client about the risks in our product and the client has to accept a disclosure/terms of service. Usually the rep will show the person the disclosure and then sometimes offer to email them a PDF version of it. We want to be able to track that the client got the disclosure and have it sent to them without them getting the rep's email. What we're imagining is a webpage with the disclosure on it and a on that says "click here to email this". That part is easy, but after they click on that on, how can an email be created and sent with the PDF in it as an attachment? And furthermore, how can we have a record that it was sent? I'm picturing those websites, usually news sites, with a link that says "email this to a friend". That would be perfect actually, but with track ability. Thanks for any help you can provide!