Microsoft has apologized for the Microsoft 365 outage that disrupted Outlook and other services across two workdays. What it still couldn’t offer as of 3:05 p.m. EST on Friday, November 13: a timetable for restoring service to everyone affected, according to Forbes. Source
Microsoft said Friday morning that some email queues were “significantly reduced and approaching normal levels,” while warning that users could still experience intermittent access problems or delayed email delivery. Source
What Microsoft says went wrong
In a Friday statement reported by ABC News, Microsoft said a recent network change exposed an issue introduced during an earlier network capacity upgrade. The company said it had addressed the underlying issue but was continuing to restore service to remaining customers and regions. Fixing the fault and getting everyone’s email moving again were still two different milestones. Source
During Thursday’s troubleshooting, Microsoft said the increased strain on its infrastructure wasn’t caused by a traffic surge. Servers had unexpectedly become unavailable, leaving the remaining systems to carry the load. The company paused deployments, moved traffic away from affected infrastructure and restarted servers as part of its response that day. SourceSource
Forbes reported Friday that Microsoft had not yet established a definitive root cause and would provide full details after mitigation. Source
Microsoft also said the technical issue was not related to cyber activity or AI agents, and that it had found no indication of malicious activity. SourceSource
A long service list, with an important asterisk
The disruption primarily affected Exchange Online, the email infrastructure serving affected Outlook mailboxes. Microsoft also identified potential connectivity problems involving Teams, SharePoint Online, Microsoft 365 Copilot and Microsoft Defender XDR. SourceSource
In its Thursday evening update, Microsoft said features that interacted with Exchange Online and email services were affected, while elements that didn’t depend on those connections remained functional, according to SecurityWeek. Source
New York City Emergency Management warned that emails to city agencies and online services relying on Microsoft systems could face delays or temporary disruptions. Source
Sports Business Journal told subscribers its Thursday Closing Bell newsletter was experiencing send delays because of the Outlook outage, directing readers to the online edition instead. Source
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