Microsoft outage: What the company has said so far

Updated on Thursday, Nov. 12 at 3:55 p.m. ET — Updated with more details revealed by Microsoft.

Microsoft is having a really bad Thursday.

Starting in the early afternoon, Microsoft 365 enterprise software products experienced a major outage, which is ongoing at the time of publication. On the platform DownDetector, more than 100,000 users reported problems with Outlook alone.

The company has posted regular updates about the situation, both on social media and on its website.

On the company’s official status page (which also went offline briefly, according to multiple Mashable reporters), Microsoft said that Exchange Online, Teams, SharePoint Online, Copilot 365, and Defender XDR were all experiencing issues. The status page also indicated that the outage is only affecting Microsoft’s enterprise software, Microsoft 365, not its consumer products.

Mashable has reached out to Microsoft for comment.

The Microsoft 365 outage: A timeline so far

And in an initial update posted at 12:54 p.m. ET to X, the company said that customers were having problems with Exchange Online mailboxes “in the Americas.” Exchange Online is a cloud-based tool that provides back-end support for Microsoft Outlook.

However, by 1:07 p.m. ET, the company acknowledged the problem was more widespread, affecting more services and regions. “While we’re working to mitigate impact, we’ve confirmed the issue may affect Microsoft 365 service connectivity for users in any region,” the company posted.

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The Microsoft Status page was then updated with a notification that stated, “User impact: Users may be unable to connect to multiple Microsoft 365 services.”

While a root cause has yet to be determined, Microsoft has at least shared a brief technical explanation for what’s going on.

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“We’ve determined that the elevated load isn’t driven by an overall increase in traffic, but by a large number of servers being unexpectedly unavailable, which is shifting load onto the remaining infrastructure,” Microsoft said on its status page, as well as in a thread on X. “We’re investigating what’s causing these servers to become unavailable while we work to safely return them to service.”

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Later on in the X thread, Microsoft said it had not identified any recent change that correlates with the outage, but “the failed health checks may originate from a specific component that’s responsible for processing server health.” In the meantime, Microsoft has worked to prevent more servers from being impacted while it also tries to resuscitate the ones that are down.

Shortly before 4 p.m. ET, the Microsoft status page received another update, stating that it is still troubleshooting and restarting servers.

“While validating the targeted change, we found that many of the affected servers have become unresponsive, which is preventing us from confirming whether the change is effective,” Microsoft said. “We’re restarting these servers so they can come back online with the change in place, and we’re applying the same approach to additional affected portions of our infrastructure to validate the results more broadly.”

This is a developing story…

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