R.I.P. U.S. Postal Service: The $3.1B Q3 loss suffered at the USPS may be the least of its headaches after a number of online startups fire up to help consumers receive, organize and respond to digital mail from one secure location. InfoTrends calls the coming onslaught of high-tech mail alternatives a "potential game-changer." Names to track in the space: Zumbox, Doxo and Manilla.