Microsoft Restores Outlook.com Service After 3 Days of Down Time

After three days of outages, Microsoft finally fully restored access to its Outlook.com email service. Without diminishing the egregious nature of such a lengthy outage for many users, Microsoft has been forthcoming about what went wrong and outlined the steps it’s taking to avoid the same problem cropping up in the future.

“This incident was a result of a failure in a caching service that interfaces with devices using Exchange ActiveSync, including most smart phones,” reads a service status report. “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, with the effect that some customers were unable to access their Outlook.com email and unable to share their SkyDrive files via email.”

Microsoft Outlook.com outage

To alleviate the problem, Microsoft temporarily blocked access via Exchange ActiveSync so it could restore Outlook.com access and SkyDrive’s sharing capabilities via the web. Then, having generated a backlog of Exchange ActiveSync requests, Microsoft brought everything back slowly--hence the extended wait for service restoration for some users.

Microsoft has boosted its network bandwidth for the part of the system that experienced the outage and also adjusted the way it handles Exchange ActiveSync errors. The outage has been completely restored now.

These things happen, we suppose, but three days is a terribly long time to have a service outage, and if Microsoft hopes to grab some user share of the email market, this can’t happen again.