SPF (Sender Protection Framework) records are used to authenticate IP addresses of e-mail senders and stop spammers from forging return e-mail addresses. But now it looks like spammers are fighting back, and registering their own SPF records!
E-mail security company MX Logic Inc report that 10 percent of all spam includes SPF records. The only hope for killing spam in this case, then, is for enterprises to increase their reliance on white lists for blocking spam. It may also be the case that spammers are supporting and adopting SPF faster than legitimate businesses are. Studies comparing spam to legitimate mail have seen 38% more spam messages using SPF than legitimate mail senders do.
Will spam never cease?