Bulk email

I want software (or plugin for Outlook/Entourage) to allow me to control spam emails. I’d like to be able to add senders to an approved list. If the sender is not on the approved list, they receive an automatic reply email requesting that they type in a verification code shown in a graphic. This allows the original message to be received but blocks automatic senders who don’t reply with the verification code. Sender may still be added to a blocked list at the user’s discretion.