Microsoft, Yahoo! and America Online are all working on methods to authenticate e-mail and make it harder for spammers to get mail through gateways.
Microsoft’s proposal, known as Caller ID for E-mail, calls for Internet service providers to submit lists of unique numeric addresses for their mail servers. On the receiving end, software would check a database to verify that a message said to come from an e-mail provider actually originated at one of its registered machines.
In January, AOL began testing a similar system called Sender Policy Framework, or SPF, which checks a different part of the message.
Yahoo’s proposed solution is a different animal. It would use encryption to digitally sign messages. If the sender or message content is altered, the signature gets rejected. Yahoo announced its proposal, DomainKeys, in December but has yet to make details public.
Read more at Globe Technology.