Cisco and Yahoo have teamed up to create a system to identify the origin of emails.

The two companies will release the technology, dubbed DomainKeys Identified Mail (DKIM), to the industry royalty-free. If it is used widely enough, they hope that spammers can be back-traced and shut down.

"E-mail fraud is a global problem that ultimately costs companies millions of dollars in direct losses, technology expenditures, lost productivity and even network downtime," said Jim Fenton, distinguished engineer at Cisco Systems.

"In accordance with our commitment to standards, Cisco is pleased to join forces with key partners such as Yahoo! on the development of an effective solution that significantly mitigates the impact of email fraud on both consumers and businesses."

The technology uses public key cryptography to allow users to verify the mail and identify legitimate messages by pinpointing the sender's domain. It also communicates with the Internet's Domain Name System (DNS) to identify the sender.

The two companies will initially target banks, utilities and ecommerce services with the technology.