The Anti-Spam Technical Alliance (ASTA), which includes Yahoo!, Microsoft, EarthLink, and America Online, Tuesday released a set of best practices and technical recommendations for thwarting spam.
The group's recommendations aim to help prevent spammers from forging email by eliminating domain spoofing through IP-based and signature-based systems. They also provide best practices for ISPs, online marketers, and consumers.
ASTA cited two "promising new methods" to verify the source of email: Authenticating senders based on IP addresses, and authenticating senders based on content signing using public/private keys to generate signatures that are used for sender verification.
"By collaborating on new ways to better identify the origin of messages, we can help lift the veil of anonymity on spammers and restore integrity of email. We encourage continued testing and public discussion in order to move toward industry-standard technical solutions," Linda Beck, EarthLink executive vice president of operations, said in a prepared statement.
Among the best practices for ISPs, ASTA recommends blocking or limiting the use of port 25, implementing rate limits on outbound email traffic, controlling automated registration of accounts, and closing open relays.
ASTA formed in April 2003 and also includes British Telecom and Comcast.