White List

technique in the SpamWars

defining a list of senders in your EMail client who you agree to get email from

• none of their messages ever get marked as Spam by your filter

• maybe it's really hard for anyone not on your White List to even get a message to you (Earth Link's non-default setting works this way, sending a bounce to the sender making them come online to fill out a form with a Captcha to get approved).

related: Buddy List