Nice idea, but the first thing that comes to my mind is there is nothing on the landing page that puts my privacy concerns to rest. I see that you mention you won't do anything shady with my data, but that is only mentioned once I click through a few pages. Maybe a small link on the homepage detailing your privacy terms and use of my data. Remember, email is one of the most privately guarded possessions one can have on the internet. It isn't something I will give random services access to without some serious vetting prior.