Spammers embrace email authentication

Spammers have adopted a new standard for email authentication much faster than legitimate emailers, according to a study from security appliance firm CipherTrust published this week
More spam than legitimate email is currently sent using Sender Policy Framework, a recently introduced email authentication protocol. According to CipherTrust's research, 34 per cent more spam is passing SPF checks than legitimate email because spammers are actively registering their SPF records.
As long as spammers comply with the protocol by not spoofing the sender address, their messages will not be stopped by SPF, which CipherTrust has supported since February 2004. CipherTrust's research among users of its own IronMail message security appliance this summer found that a spam message is three times more likely to pass an SPF check than it is to fail it.