We explore an alternative approach to spam based on eco-nomic rather than technological or regulatory screening mech-anisms. We employ a model of email value which sup-ports two intuitive notions: 1) mechanisms designed to pro-mote valuable communication can often outperform those designed merely to block wasteful communication, and 2) designers of such mechanisms should shift focus away from the information in the message to the information known to the sender. We then use principles of information asymme-try to cause people who knowingly misuse communication to incur higher costs than those who do not. In certain cases, though not all, we can show this approach leaves re-cipients better off than even an idealized or “perfect ” filter that costs nothing and makes no mistakes. Our mechanism also accounts for individual differences in opportunity costs, and allows for bi-directional wealth transfers while facilitat-ing both sender signaling and recipient screening. 1