Sending messages using a false address is a common tactic of spammers. Known as DKIM, the e-mail authentication technology uses key cryptography that allows users to verify and maintain message integrity, and identifies legitimate messages. It's useful for companies that send transactional e-mail to consumers, including banks, telecoms, and online merchants.
Being offered to the industry royalty-free, DKIM borrows elements from Yahoo!'s DomainKeys and the network equipment maker's Internet Identified Mail system. And while technical differences exist, each attaches a scrambled digital signature to a user's mail, which can then be vetted to ensure that it's actually being sent from the domain in the sender's address.
Both Yahoo!'s e-mail service and Google's Gmail e-mail have initiated DomainKeys, and a huge demand for just such a collaboration existed, according to Miles Libbey, anti-spam product manager for Yahoo! Mail.
"Yahoo! is receiving more than 350 million messages signed by DomainKeys per day," Libbey said in a statement. "By collaborating with innovative companies such as Cisco and Sendmail, we have been able to tap into industry visionaries like Sendmail's Eric Allman to help combat e-mail forgery. In doing so, we can offer a solution that increases the level of defense against fraudulent e-mails and phishing attacks."