Messages from its free e-mail service will include a "DomainKey," a system that creates a digital signature for outgoing e-mail and then lets receivers verify that the message comes from where it claims. The technology tries to thwart spam "phishing" attacks in which messages pretend to originate from a familiar address and then launch viruses or social engineering hacks when opened.
The changes won't be noticeable to the Yahoo Mail user, since DomainKeys are resolved in Yahoo's servers and network infrastructure.
Users "simply use Yahoo Mail and get the benefit of knowing that we use DomainKeys to prevent attacks," said Brad Garlinghouse, vice president of communications products at Yahoo.
Yahoo has talked up DomainKeys as a powerful weapon against spam, for the system to work, but outgoing and incoming e-mail services must use the keys. So far, Yahoo has picked up endorsements from EarthLink and. But the biggest e-mail providers, America Online and Microsoft, remain in the wings.
AOL and Microsoft have said they're looking at DomainKeys, but the providers areand e-mail authentication technologies. AOL's SPF and Microsoft's Sender ID check an e-mail's identity through its Internet Protocol address, and can be used alongside DomainKeys.
Yahoo and Microsoft have filed with the Internet Engineering Task Force for their technologies to become standards. Meng Wong, SPF author and chief technology officer of Pobox.com, filed for standardization with the IETF as well.
Up to their ears in storage
Also on Monday, Yahoo introduced yet another storage upgrade to its e-mail service, this time to 250MB, up from a boost to . Yahoo and Microsoft's Hotmail have made such moves following with Gmail, which launched in beta form with 1GB of free in-box storage.
Until that point, Yahoo and Hotmail offered 4MB and 2MB of free storage, respectively, and charged fees for people requesting extra space.
In addition, Yahoo said Monday it will increase the attachment limit for its premium subscribers to 20MB, while free e-mail users will get 10MB.