Bulk Mailer with Google App Engine

I currently run a website that runs on its own server. User data is kept in a MySQL database on the server. I'd like someone to write an application that uses Google App Engine's email capabilities to send emails to the userbase. As such, the application needs to be able to do the following things: * Get a list of users & email addresses from a MySQL database and pass that to Google App Engine to use * Use Google App Engine to send out emails to those users * Provide an area for me to paste a HTML email into a form and see a preview before sending it * Convert the HTML email to plain text for both types of email * Replace certain values in the HTML / plain emails with database data (allowing custom usernames + unsubscribe URLs in each email sent out, for example) * Handle and record bounce backs / invalid emails etc * Take this bounce back / invalid email information and update the MySQL database so those users don't get emails in future mail outs This should all be possible using Google App Engine's Mail API and Remote API. Thanks.