Monday December 15, 2003If email is the internet's killer-app, then the growing prevalence of spam (unsolicited bulk email) is throttling the internet's most compelling benefit. Increasingly, spam is choking mailboxes and costing millions of person-hours a year as people need to sort through the mire to extract mission-critical business communication. According to measurements from Brightmail's Probe Network, spam has hit the 56 percent mark (i.e. 56% of all e-mail was classified as spam).