17 September 2004 Internet giant America Online (AOL) has announced that it will no longer use Microsoft’s Sender ID technology, favouring instead Sender Policy Framework (SPF), a more open alternative.

AOL cited as its main reason for migrating to SPF that software giant Microsoft’s technology is inadequate. The Internet Engineering Task Force (IETF), the main Internet standards body, expressed concerns with Sender ID earlier this week, which may also have prompted AOL’s decision.

In a statement, AOL noted that the company has “serious technical concerns that Sender ID appears not to be fully, backwardly compatible with the original SPF specification – a result of recent changes to the protocol and wholesale change from what was first envisioned in the original Sender ID plan.”

The Sender ID Framework, like SPF, is an industry standard created to fight spam and to provide greater protection against phishing and other malware schemes. However, Microsoft is only making its Sender ID technology available on a royalty-free basis, ruling out its incorporation into open source tools such as the Sendmail email server.

Now, a battle is looming at the IETF regarding anti-spam authentication technology, with the balance tipped in recent weeks in SPF’s favour.

However, although AOL will move to SPF, the company still intends to publish Sender ID files so that users of the technology can still employ applications that relate to Sender ID.