US-based technology giant Microsoft on Friday admitted that its fixes are not “working as expected” as a mega outage hit millions of users across Microsoft 365 services globally.
In a statement on X, the company said it had monitored the status of the changes applied to improve serviceability and confirmed they were not taking effect as expected.
“We’re identifying alternate workstreams that can be applied to increase capacity in the face of sustained traffic management imbalances,” Microsoft said.
According to Microsoft, users may be unable to connect to multiple Microsoft 365 services with features interacting with Exchange Online and email services impacted.
Exchange Online users may be unable to access their mailbox using Outlook on the web, Outlook desktop, Exchange ActiveSync or REST-based connections, and email delivery may be delayed, according to the company.
The Microsoft 365 admin center pages also may fail to load, while Microsoft 365 apps users may be unable to view recently used files.
Similarly, Microsoft Copilot 365 users may be unable to load Copilot Chat or receive responses and Copilot experiences may be unable to access work data such as email, calendar and files.
We’re opening all available pathways to restore service, as our actions taken thus far have not provided the anticipated relief. We found a core process on affected servers is becoming overwhelmed, causing capacity loss. To validate a potential recovery, we’re isolating a portion of infrastructure, restarting affected components, and reintroducing traffic to confirm the services remain stable before applying the change more broadly. More info under EX1550543 and MO1550821 in the Microsoft 365 admin center, as well as if the admin center is not available to you.
— Microsoft 365 Status (@MSFT365Status) November 12, 2026
Microsoft Teams’ core functionality, including joining calls, meetings, group chats and channel messages, was largely not impacted, the company said.
But calendar-related failures, creation of Live or Virtual events, Copilot responses and contact syncing were affected, it added.
Other impacted services include Microsoft Defender for Office 365 and Defender XDR, Microsoft Fabric, Microsoft Graph, Microsoft Intune, Microsoft Planner, Microsoft Purview, Microsoft To Do, Power BI, SharePoint Online, Universal Print and Windows 365.
“As part of our investigation into the sustained traffic management imbalances, we’re reviewing traffic flows and affected infrastructure to identify opportunities to optimise routing. This includes verifying the reasons for service failures so we can develop specific actions to improve stability,” Microsoft said in its status update.
When will the services be fully restored?
The company began working on restoring affected infrastructure by redistributing connection traffic across its worldwide network. It said it was moving additional traffic away from affected infrastructure to reduce the load on operational servers and restarting affected servers to bring them back online.
Microsoft said: “We’ve paused all deployments. We’re moving additional traffic off the affected infrastructure, and we’re restarting affected servers to return them to service.”
We’re investigating reports of users experiencing issues accessing Exchange Online mailboxes through multiple connection methods in the Americas. More details can be found in the Microsoft 365 admin center under EX1550543.
— Microsoft 365 Status (@MSFT365Status) November 12, 2026
Microsoft subsequently tested an alternative server health-check method, which allowed a portion of the affected servers to return to service. It said it would apply the change more broadly and prepare automated recovery systems to identify and restart unresponsive servers.
By around 4:30 am IST on November 13, Microsoft reported limited recovery, with some users gradually reconnecting to its services.