Originally shared by Edward Vielmetti
Microsoft’s Outlook.com service was down; here’s the writeup. " The failure caused these devices to receive an error and continuously try to connect to our service. This resulted in a flood of traffic that our services did not handle properly, "
http://thenextweb.com/microsoft/2013/08/17/microsoft-apologizes-for-three-day-outlook-com-outage-says-caching-issue-was-to-blame/