Rafe Needleman writes about TurnTide, a new startup with a very clever method for reducing the flood of spam coming into businesses and ISPs:
bq. "Unlike the other anti-spam products I know of, TurnTide doesn't actually block messages. Instead, through clever technology, it increases the senders' cost of sending bulk e-mail, rendering a large spam target, like an enterprise, unattractive."
I must admit, this use of dynamic "traffic shaping" is pretty clever - and it does avoid many of the issues with existing anti-spam solutions.
This technique is available without the hardware. Mail servers can 'trap' incoming emails from spammers increasing a delay , thus slowing down the email server the spammer is using.
A number of honey pots use this method.
Where this doesn't work is when spammers use open mail relays or trojaned PCs. Then it's some else computer that slows down to a crawl. The spammers move elsewhere.