E-mail authentication is here, but has it arrived yet?

The explosion in spam and phishing attacks has cost victims time and money. The attacks have also dented public confidence in e-mail. Attempts to solve the problem by the multimillion-dollar mail-filtering industry or via legislation have failed. In light of this, companies such as Cisco Systems, Microsoft, and Yahoo are pursuing e-mail authentication, designed to determine whether mail has come from a reliable source and is thus legitimate. The article looks at some of the methods being considered.