EC2 wasn't really designed to be used for public-facing services that require static IP addresses or reverse DNS. Developers are shoehorning public-facing apps

EC2 wasn't really designed to be used for public-facing services that require static IP addresses or reverse DNS. Developers are shoehorning public-facing apps on to EC2 instances anyway, and it's great that EC2 provides the flexibility to allow that... but that never was its intended goal. If you're worried about incoming mail, why not just use a service designed for it, like fastmail.fm?