Someone wondered about this in another HN thread (which is what led to this question being asked), and personally I find it astonishing that there's a bunch of

Someone wondered about this in another HN thread (which is what led to this question being asked), and personally I find it astonishing that there's a bunch of hackers here that don't know how email works or what an MX record is. I guess in this age of Amazon this and cloud that, nobody bothers to learn how these things work as long as they can run their webscale node app written in CoffeeScript on their cloud servers.