I'm still new to freelancer, but not to systems engineering. In a previous life, I ran the systems, including email, for a major e-greeting company, back when that was all the rage. We would process up to 20 million emails per day, and the bounce rate hovered around 10% fairly consistently. Two million bounces, every day. So of course I built a way to prevent those same addresses from reoccurring.
Using SES and SNS, most of the heavy lifting will be done. I'll create a web app that SNS will connect to, and will configure it to use an authentication token that will be installed on SNS (it will be a part of the JSON data SNS sends), to prevent hackers from corrupting your database. The app will then update the database, as appropriate.