Face palm: Microsoft is struggling to restore its services after a massive outage worldwide disrupted Outlook, Teams and other applications for several hours on Thursday. The company says it has “no evidence of a cyberattack” and is continuing to try to get all affected services back up and running.
Users began reporting issues with several Microsoft 365 services on Thursday morning. The outage detection website Down Detector received nearly 150,000 reports of people unable to access Word, Excel, PowerPoint, Outlook, Teams, Copilot and other Microsoft services.
Microsoft confirmed the outage and said it was investigating reports of “users having issues accessing Exchange Online mailboxes using multiple connection methods.” Some time later, the company reported that its server infrastructure was “experiencing increased utilization, which likely contributed to the connection failures.”
— Microsoft 365 Status (@MSFT365Status) November 12, 2026
By evening, Microsoft was able to restore some services, but more than 10,000 people still reported that they were unable to access some of Microsoft’s largest and most used online services. One of the hardest-hit services was Outlook, whose users complained that they were unable to send email or even access their inbox.
Microsoft later said it tried to mitigate connectivity issues by restarting and validating affected servers to get them back up and running. It also said engineers were checking whether recent configuration updates caused the problems and whether restoring them could help speed recovery.
Unfortunately, the company has since reported that some of the affected servers that were brought back online “became unresponsive again as soon as they received traffic.” Microsoft says it is analyzing diagnostic data from unresponsive servers as part of its investigation and is also “temporarily limiting what types of traffic can reach the affected infrastructure in some regions.”
— Microsoft 365 Status (@MSFT365Status) November 13, 2026
In the last hour, Microsoft has again released an update saying that the fixes are not working as expected and that some users are still having problems accessing its services. “We are identifying alternative workflows that can be used to increase capacity amid ongoing imbalances in traffic management,” the company added.
The outage not only affected general users and global organizations, but also several AI companies, including Anthropic and OpenAI. Both reportedly use Microsoft 365 in their offices and have released separate statements saying they are investigating serious connectivity issues with Microsoft’s services that are causing some productivity tools to not work as expected.
Microsoft hasn’t revealed any key details about the outage, but some researchers believe they know exactly what’s happening. Mark Gregory, associate professor at RMIT University’s School of Engineering, told The Guardian that the outage is likely to affect the network layer in Microsoft’s systems and may be similar to the configuration issue that crashed Optus’ network in 2023.
According to Gregory, when some configuration servers experience connectivity issues, users are forced to share the smaller pool of servers that are still online. If the outage continues, the live servers often crash due to overload, which is exactly what seems to be the case in this case. We’ll have to wait until Microsoft completes its investigation to learn more.
