Microsoft 365 outage has disrupted cloud services across 74 countries, affecting Outlook, Teams, Copilot and enterprise applications with engineers starting to fully restore servers and contain cascading infrastructure failures.
Microsoft says it is “observing sustained improvements in service availability” as the outage causing worldwide disruption continues.
The company confirmed recovery was progressing across affected Microsoft 365 services that went down on Thursday (Sept 12) evening.
In a status update, the company has said: “We’re observing sustained improvements in service availability as recovery progresses across affected Microsoft 365 services. While service functionality continues to improve, some users may still experience intermittent connectivity issues or delayed email delivery.
The outage is one of the longest and most disruptive that Microsoft 365 has ever suffered
Earlier today (Friday 13) Microsoft said continued recovery was progressing across affected regions, with broader improvements observed in North America and sustained improvements across much of Europe.
“We’re also seeing encouraging recovery signals in Asia Pacific, although some users may continue to experience intermittent access issues or delayed email delivery as mitigation progresses across the remaining affected infrastructure,” the company said.Microsoft is starting to restore its cloud services after a major outage knocked out Outlook, Teams and other Microsoft 365 applications across 74 countries.
Nearly 130,000 problems were reported worldwide as businesses and individual users lost access to critical productivity, email and communications services. The outage also affected Microsoft’s Copilot AI assistant, SharePoint and OneDrive, raising concerns about the resilience of enterprise cloud infrastructure.
Microsoft said it was investigating possible server configuration failures, although a company spokesperson confirmed there was “no indication of a cyber-attack”.
Downdetector recorded a sharp increase in Microsoft 365 problems from around 1pm ET affecting access to Word, Excel, PowerPoint, Outlook and Teams.
Enterprise services including SharePoint and OneDrive were also disrupted, alongside Microsoft’s AI assistant Copilot.
Microsoft suggested the outage may have been caused by problems with configuration settings applied to servers responsible for maintaining Microsoft 365 services.
Throughout the disruption, engineers attempted several recovery measures, including rolling back updates and restricting traffic to affected servers.
However, Microsoft reported that servers became unavailable again when normal traffic levels returned, complicating efforts to restore services.
Exchange services, which support Outlook email, were experiencing the most significant disruption, with knock-on effects across dependent applications. Teams chats and meetings were less severely affected.
Microsoft earlier reported that part of its infrastructure was “experiencing elevated load”, which was “likely contributing to the connectivity errors”.
Investigations identified several servers that were “unexpectedly unavailable” following failures during automated checks.
Posting on X, Microsoft said it was “investigating reports of users experiencing issues accessing Exchange Online mailboxes through multiple connection methods”.
The company subsequently reported that restored servers had remained stable and that engineers were redirecting traffic through alternative routes while accelerating recovery of the remaining affected infrastructure.
“As capacity is restored, users may experience a gradual recovery as their clients reconnect,” a company statement said.
The outage also affected connectors used by OpenAI and Anthropic to integrate AI services with Microsoft platforms.
OpenAI reported that it was investigating problems with Microsoft connectors, including failures affecting new connections and tools that were not operating as expected.
