Early versions of the spam-filtering technology, which was developed by Microsoft Research, have already been introduced in Outlook 2003, MSN 8 and Hotmail. It will also be available in a new add-on for Exchange Server 2003 called Microsoft Exchange Intelligent Message Filter.
Ryan Hamlin, general manager of the anti-spam technology and strategy group at Microsoft, said, "Spam is our e-mail customers' number one complaint, and although there is no single solution that will solve the problem by itself, we are committed to innovating on a broad spectrum of approaches to help put spammers out of business."
Graham Cluley, senior technology consultant at anti-virus firm Sophos, said, "Microsoft is taking spam seriously. That means that other business users get the message that spam is a real security issue.
"Any large business that is communicating seriously over the internet needs to have a filtering policy for viruses and spam, as well as a general e-mail policy."
Smart Screen is based on a machine-learning approach, where user decisions about which e-mails are spam are incorporated into a feedback loop to train the filter what to look for.
With the Exchange Intelligent Message Filter, Exchange 2003 users can score each incoming e-mail message for spam probability according to a range of characteristics and can use that score to filter spam before it reaches the user's inbox.