IETF Approves SPF and Sender-ID
NW writes "According to the records in the IETF's database (here and here), both the SPF and Sender-ID anti-spam proposals were tentatively approved by the IESG (the approval board of the IETF) as experimental standards. It remains to be seen whether any of them will actually put a dent into spam." At the same time, the FTC has opened a central site about email authentication.
When implementing SPF, you have to make sure that all systems authorized to send mail from your domain are listed. In other words, if it doesn't come from "mail.earthlink.net," SPF will reject it.
Another one bites the dust