Microsoft blames server outages for widespread Microsoft 365 disruptions

Microsoft said Thursday that unexpectedly unavailable servers, rather than increased user traffic, were behind widespread connectivity problems affecting its Microsoft 365 services across multiple regions.

In its latest update on US social media platform X, Microsoft 365 Status said the outages had placed additional strain on the remaining infrastructure.

“We determined the elevated load isn't driven by an increase in traffic, but by a number of servers being unexpectedly unavailable,” the company said, adding that it was working to safely bring the affected servers back online.

The disruption affected access to Exchange Online mailboxes and potentially other Microsoft 365 services, with users reporting connectivity problems through various access methods.

Microsoft said it had paused all deployments, redirected traffic away from affected infrastructure and restarted impacted servers as part of its recovery efforts.

Earlier, the company reported elevated infrastructure loads across multiple regions and said it was redistributing connection traffic across its global network to ease the disruption.

Outage-tracking website Downdetector recorded more than 97,000 reports of Outlook problems, over 38,000 complaints involving Microsoft 365 and around 4,500 reports related to Teams in the US.

The actual number of affected users may differ, as Downdetector relies on user-submitted reports.

Microsoft directed users to its service status website and the Microsoft 365 admin center for updates under incident references EX1550543 and MO1550821.