You're a Whitelist Program!

A whitelist program, such as MailFrontier, acts as your doorman: Mail senders not on your guest list are asked to state their reason for writing you, or to go to a Web page and type in a word shown there, to weed out automated mailers.

But friends and strangers may bristle at being asked to prove themselves to a computer, causing you to miss out on potential new contacts or tips from outside your inner circle. Kevin Werbach, who wrote about whitelists in Slate, says he doesn't use them himself for these reasons.

In a past life you might have been:
A Bayesian filter
A Collaborative filter
No filter at all