Looking to make an anonymous email service

I need a nice, modern landing page for the website. This landing page should give the visitors an opportunity to send an email to a friend, or coworker, very similar to [login to view URL] There are however a few major differences: -The visitor will be limited to 1 email/hour for free. You should use persistent cookies and IP address logging to make sure this happens. I am open to suggestions if you have a better idea. -There will be a paid version which will allow the user to send more than 1 email per hour. This limit should be set in the admin panel. The user should have a place to sign in/signup. There should be a Paypal payment gateway. -The admin panel will allow the administrator to set the prices, the payment gateway, and a few other things. -The freelancer should fine the most effective system to send the email. Current debate is between sendgrid, mandrill, and phpmailer Other requirements will be sent directly to the freelancer.