[lucb1e]

Fun, but it doesn't scale. Google can only do this because they have a near-monopoly on email. What would you say if I gave you tools to whitelist yourself on my email server? You'd tell me to get my spamfilter straight, or more likely, simply ignore me.

I'm not against Gmail, just like I'm not against Outlook.com or Yahoo mail or something. It's just that providing tools only work for players in a power position (i.e. Google) who can afford to ignore small players (i.e. me), and what's more, this further strengthens their power position: the better they can detect spam so more people will start using it (the postmaster tools are there to help people prove they are good, thus helping Gmail distinguish).