On Monday, the Sunnyvale, Calif., company will begin to support its DomainKeys cryptographic approach for Yahoo Mail, one of the largest Web-based e-mail services in the world.
Yahoos DomainKeys move will come as part of a series of enhancements to Yahoo Mail. The company will announce that it has increased the storage limit for free e-mail accounts from 100MB to 250MB and has raised the maximum attachment size for premium accounts from 10MB to 20MB.
By supporting DomainKeys on its own service, Yahoo hopes to jump-start broader adoption of its answer to stemming the rise of spam and phishing attacks through e-mail.
Online attackers regularly send unsolicited e-mails and lure consumers into clicking malicious links or providing personal information by disguising their e-mail addresses with the domains of major consumer companies.
"By implementing and deploying DomainKeys, were showing that the cryptographic solution is not only the long-term answer but todays answer as well," said Miles Libbey, anti-spam product manager for Yahoo Mail.
DomainKeys uses public/private key cryptography to verify the sender of an e-mail at the level of an Internet domain, such as yahoo.com. Like other authentication methods, it requires that both the sending and receiving e-mail servers implement the technology.
Yahoo over the past week has begun supporting the signing of outgoing mail using DomainKeys, Libbey said. On Monday, it will start verifying incoming mail. The rollout will begin with U.S. accounts and expand internationally by the end of the year, he said.
Leading ISP EarthLink Inc. on Monday also plans to announce that it will begin testing DomainKeys in the next few weeks.
Other early adopters of DomainKeys include top Yahoo competitor Google Inc., which is supporting the method on outgoing mail from its Gmail service, Libbey said. America Online Inc. also has expressed interest in testing DomainKeys, he said.