The Microsoft 365 outage has stretched into a second day, hitting Outlook, Teams, Copilot, and Exchange Online while Microsoft has yet to give a time for full recovery.
- The Microsoft 365 outage began on Thursday and has now continued into a second day, affecting organizations around the world.
- Outlook, Exchange Online, Teams, and Copilot are among the affected services.
- The cause was a number of backend servers unexpectedly going offline, which overloaded the remaining servers.
- Microsoft has deployed a fix for the authentication and routing component, and extended the email retry window to 48 hours.
- The company says it has seen no sign of a malicious attack, but has not given a time for full recovery.
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How the outage unfolded
Several Microsoft services, including Outlook, Teams, Copilot, and Exchange Online, have suffered widespread disruption since Thursday. On the second day, businesses, government agencies, and other organizations around the world are still affected. Microsoft has been working on the problem for many hours but has not fully resolved it.
According to the company's incident report, the Exchange Online fault appeared at around 11:17 a.m. ET on November 12. By 1:26 p.m. the same day, the problem had spread across all of Microsoft 365. Since then, Microsoft has acknowledged the issue and has posted regular updates on its progress.
Affected services
Outlook and Exchange Online took the heaviest hit. Users reported trouble accessing mailboxes, sending email, or receiving new messages. Microsoft Teams also ran into problems, mainly with calendar and meeting scheduling features. Core messaging and calling still worked for many users.
Microsoft 365 Copilot was affected too, with some users unable to open conversations or retrieve information. The list also includes SharePoint Online, Microsoft Defender XDR, Intune, Planner, and To Do.
Among consumer services, Microsoft listed Outlook.com, OneDrive, OneNote, and the web version of Microsoft 365 as potentially affected. Not every feature in these apps has stopped working. The level of disruption varies from case to case.
Cause and recovery progress
Microsoft initially suspected an unusual spike in traffic. Deeper investigation showed that some backend servers had unexpectedly become unavailable. The remaining servers had to absorb the entire load and were overwhelmed.
The company tried restarting some of the faulty servers. However, once traffic was restored, those servers stopped responding again. Microsoft then deployed a fix targeting the authentication and routing component, and the fix appears to be taking effect.
In its latest detailed update, Microsoft said it has seen early signs of recovery, though server capacity remains below normal. Engineers are continuing to restore traffic and bring more servers back online. The company also extended the email retry window to 48 hours so that delayed messages are not lost. Microsoft maintains there is no sign of malicious activity behind the outage, but has not said when full recovery will be complete.
For organizations that rely on Microsoft 365 as their main workplace platform, this outage is a reminder to keep a backup communication channel for times when email and meeting calendars are down. Microsoft extending the email retry window to 48 hours lowers the risk of lost messages. Even so, users should keep watching the company's service status page for recovery updates.
Source: Digital Trends
Reviewed by: Hero Association
