One leader in the field declares that the basic parameters of spam fighting are all set and real research is over.
Anti-spam research isn't really all that old, as security research fields go, but it may have hit the end of the line. A thread in the mailing list of the Internet Engineering Task Force's Anti-Spam Research Group (ASRG) argues that all the basic questions have been answered.
Phillip Hallam-Baker, CTO of VeriSign, argues that, "It is now accepted that there are two approaches to stopping spam, filtering out the bad stuff, making it easier to identify the good stuff."
There is a third way
Nothing in this writer’s research has explained why VISA, Mastercard, et al, tolerate spammers. Without credit cards spamming would not be possible. So why do these companies traffic with such operators? We need to make this a customer relations issue.