This sounds like a neat idea. You select an @duck.com email address that you can give out to others or use when signing up for services online. When the email address receives a message, DuckDuckGo removes trackers from the email and forwards it to your normal email address.
It does leave me wondering how long it will be before they offer a true email service, though, with custom domain support and all. It would be cool to get these features from DuckDuckGo while still being able to use my own email address with my domain.