From Wired:
Internet portal Yahoo released an e-mail standard Tuesday that prevents spammers from hiding unwanted messages behind legitimate e-mail addresses.
The technique, if widely adopted, could help Internet service providers more easily block the unwanted bulk messages that currently account for up to two-thirds of all e-mail traffic.
Yahoo's proposed standard, known as DomainKeys, would embed outgoing messages with an encrypted digital signature matched to a signature on the server that sends the message.
Internet service providers could check the signatures on incoming messages and block those that do not match up.
The procedure would be invisible to regular e-mail users because it would be implemented by e-mail providers, Yahoo said on a Web page that describes the standard.
Internet providers deploy a barrage of filters to weed out spam, and large providers like Time Warner's America Online block up to 2.5 billion spam e-mails each day.
The technique could also block fraudulent "phishing" attacks, in which scam artists attempt to collect credit card numbers and other sensitive information by posing as companies like Citigroup and eBay, Yahoo said.
Anything to stop the spam. You have no idea how much of my day is dedicated to weeding out spam and making sure I'm not filtering out legitimate messages.
You can read more information about DomainKeys here.