Yahoo and Cisco have decided that the level of commercial unwanted e-mails (in other words spam) has reached an alarming level and it's time to do something about it

The partnership between the two companies "gave birth" to a solution called DomainKeys Identified Mail, or DKIM, which combines Yahoo's DomainKeys technology with Cisco' Internet Identified Mail.

DomainKeys is a system that uses private encrypting keys to generate a digital signature which will be included in the e-mail's header. The recipient will have access to a public access key to verify the signature; the public access key which was previously published in Domain Name System.

The same concept is used by DKIM, which adds to it the Identified Internet Mail technology whose purpose is to insert the signature in the e-mail's header.

In this way, DKIM eliminates the possibility of spam messages to be sent from false e-mail addresses.

In Cisco's and Yahoo's opinion, this technology is aimed at e-mail clients which involve transactions, like e-commerce sites and banks.

Yahoo took the opportunity and announced that it will release other anti-spam solutions as well.