Microsoft's Sender ID framework and SmartScreen, and IBM Research's Activity Explorer are among new e-mail technologies that will make e-mail more productive and give it new roles in the next few years. Sender ID Framework verifies that a message was really sent from a server that is authorized to send mail for the domain owner. John Scarrow of Microsoft says 73 percent of Fortune 100 companies use Sender ID, which is used for 31 percent of all e-mail messages. Yahoo! and Cisco have submitted the proposed DomainKeys Identified Mail (DKIM) standard, which would guard against spoofing and phishing by authenticating an e-mail sender, to the Internet Engineering Task Force (IETF). Microsoft also provides SmartScreen filter, which employs statistical methods to learn what is spam and what is not, as well as the Phishing Filter add-in for the MSN Search Toolbar. Microsoft researchers say the ultimate solution might be a four-pronged approach involving a machine learning filter, triggered replies that challenge senders to prove that they are not spammers, having the sender solve a puzzle that is easy for people to solve but difficult to solve for an automatic spam generator, and delivery assurance with credit-card-based micropayments that can be refunded to the sender if the message is not spam or paid out in various ways. The IBM Activity Explorer, a collaboration tool, aggregates e-mail messages, synchronous communication, screen images, files, folders, and to-do lists. A team can build activity threads that contain such feeds and switch without difficulty between asynchronous and real-time collaboration.