Spamhole

Via Slashdot comes this link to a project to help reduce spam.

Spamhole is not a personal solution, but a server-side one. As I understand it, it leaves an open relay for spammers to sniff out, like a honeypot. Spammers see the open relay as an opportunity to exploit the server they find it on, hijacking the server to send out their spam. But what Spamhole does is to set thresholds that spammers won't normally rise above, identifying them. The mails they send are then accepted by the server and promptly deleted! The spammer thinks they went out, but 'Net traffic is dramatically reduced because the spam dies at the source.

Spammers never know which relay is real or a trap. It forces them to work harder, making spam more expensive and therefore less attractive. It's an elegant idea.