Outlook and Microsoft 365 outage: November 12, 2026
Outlook stopped loading for people around the world on Thursday. This page tracks what Microsoft has said, in order, with the time of each statement.
Not resolved as of 9:07 p.m. Central, November 12. All times are US Central.
What failed
Microsoft says a process on the affected servers that sets up secure connections becomes overwhelmed, and the servers stop processing requests.
What Microsoft is doing
Looking for other ways to add capacity after its latest changes did not take as expected. Earlier steps included restarting the affected servers, limiting some traffic in specific locations, and reverting a recent network configuration change that correlates with the start of the outage.
What is not known
Microsoft has not confirmed a root cause and has not given a time for full restoration. Recoveries on Thursday evening have stalled more than once.
The story so far
Outlook stopped loading for people around the world shortly before noon Central on Thursday, November 12, 2026. Downdetector logged more than 100,000 reports, and Microsoft said it was investigating problems reaching Exchange Online mailboxes that could affect Microsoft 365 users in any region.
By early afternoon Microsoft said the cause was not a surge in traffic. A number of servers had become unexpectedly unavailable after failing automated health checks, and that strained the rest of its infrastructure. Reports peaked near 130,000.
The afternoon brought a series of fixes that each fell short. A targeted change to bypass the component behind the failed health checks ran into servers that had become unresponsive. An alternative health check brought a subset of servers back at about 3 p.m. At 4:09 p.m. Microsoft said its actions "have not provided the anticipated relief" and that a core process on the affected servers was becoming overwhelmed.
The evening followed the same pattern. At about 5:30 p.m. a portion of servers returned and looked stable. By 6:06 p.m. Microsoft said those servers could become unresponsive again once they received traffic. At 7:06 p.m. it described the process involved, one that establishes secure connections, and began reverting a recent network configuration change that correlates with the start of the outage. Restarts showed positive results at 7:50 p.m., but at 9:07 p.m. Microsoft said the change was not taking as expected.
Throughout, Microsoft has said the problem centers on email. Most core Teams functionality keeps working, and files stored directly in SharePoint Online can still be opened. Downdetector counted reports from 74 countries and territories in about an hour, with Outlook reports at more than 2,000 times their normal level.
Timeline
Newest firstThe fix is "not taking as expected"
Microsoft says it monitored the changes it applied to improve serviceability and confirmed the change is not taking as expected. It is identifying alternate workstreams to increase capacity in the face of sustained traffic management imbalances.
Source: Microsoft service health status
Capacity is added for regions coming online
Microsoft says it is applying infrastructure capacity improvements where possible to support traffic in regions coming online, and is monitoring the results of the changes it has applied.
Source: Microsoft service health status
Microsoft reports positive results from server restarts
Microsoft says it is seeing positive results from restarting the affected infrastructure. It is monitoring those servers to verify they stay stable and says remediation will be expanded as stability is confirmed.
Source: Microsoft service health status
The failing process is identified and a rollback begins
Microsoft says a process responsible for establishing secure connections becomes overwhelmed, causing servers to stop processing requests. It is validating a configuration change on a subset of servers and has begun reverting a recent network configuration change that correlates with the start of impact. It has not called that change the cause.
Source: Microsoft service health status
The list of affected services is revised
Microsoft publishes a revised list of impacted services and features. Features that depend on Exchange Online and email are affected; parts of those services that do not depend on email keep working.
Source: Microsoft service health status
Recovery hits a setback
Microsoft says the servers it returned to service can become unresponsive again once they receive traffic. It starts limiting which types of traffic can reach the affected infrastructure in some locations, and rebuilds a subset of servers using a previous configuration.
Source: Microsoft 365 Status on X
A portion of servers returns to service
Microsoft says it is returning a portion of the affected servers to service and that they remain stable so far. It describes recovery as gradual. TechRadar warns that phishing emails often follow outages.
Source: TechRadar live coverage
The outage by the numbers
Downdetector reports problems from 74 countries and territories in about an hour, Outlook reports at more than 2,000 times their normal level, and 19,650 reports a minute across five Microsoft services. Microsoft says it is investigating a small number of configuration updates as possible contributors.
Source: Tom's Guide live coverage
Microsoft says its fixes have not worked
Microsoft says its actions so far "have not provided the anticipated relief." It finds that a core process on affected servers is becoming overwhelmed, causing capacity loss, and begins isolating a portion of infrastructure to test a recovery.
Source: Microsoft 365 Status on X
First servers are back
Microsoft says it has validated an alternative service health check method and that a subset of affected servers has returned to service. It applies the change more broadly, with automated systems restarting unresponsive servers.
Source: TechRadar live coverage
The first fix hits a snag
Microsoft deploys a targeted change that bypasses the component behind the failed health checks. While validating it, Microsoft finds many affected servers have become unresponsive and restarts them with the change in place. Outage reports are down to about 61,000.
Source: Tom's Guide live coverage
Still not fixed
Microsoft says the failed health checks may come from one specific component and that it has stopped more servers from being affected. It has not found a recent change tied to the start of the outage. Reports fall to about 77,000 from a peak near 130,000.
Source: TechRadar live coverage
Microsoft explains what went wrong
Microsoft says the problem was not a surge in traffic. A number of servers became unexpectedly unavailable after failing automated health checks, which strained the remaining infrastructure. It pauses deployments, restarts affected servers and tests a configuration change.
Source: Microsoft 365 Status on X
Microsoft confirms a widespread outage
Downdetector logs more than 100,000 outage reports. Microsoft says it is investigating problems reaching Exchange Online mailboxes that may affect Microsoft 365 users in any region. No cause and no time for a fix.
Source: 9to5Mac
