Seems like all the comments here are very negative. On a meta-question, why would that link be ranked #1 ?! I mean, sure, someone can upvote the link and write a negative comment, but that's unlikely.

That being said, I think this could be a useful javascript plugin.. I.e. when you click a mailto link, you get a contact form in an overlay, maybe with a "Send this email from my email client" for people who prefer to use native or gmail clients. As to actually send the email, it could simply use sendgrid or a post call to the backend.