Key Notes
- A Microsoft 365 outage disrupted Outlook, Teams and other services from Thursday into Friday.
- Japanese banks and brokers warned customers about email and service interruptions.
- Microsoft reported improving server stability while continuing work toward sustained recovery.
A widespread Microsoft (Nasdaq: MSFT) outage disrupted banks, businesses and government agencies on Friday as problems with Outlook, Teams and other Microsoft 365 services stretched from the American workday into Asia and Europe.
The disruption began shortly before 1 p.m. Eastern on Thursday, November 12, and continued into Friday morning. Email, calendars and services connected to Exchange Online were affected, along with parts of SharePoint and Copilot. Microsoft’s service notice said core Teams calls, meetings and messaging remained functional, while calendar features and other Exchange-linked functions were affected.
Downdetector received complaints from 74 countries and territories within about an hour. US reports of Outlook problems approached 130,000 at the peak.
Japanese Banks and Brokers Warn Customers
Japan Post Bank warned that customers using Outlook might not receive one-time passwords, transaction notifications or messages needed for account-opening and card applications. It said some procedures could still be completed using a different email address.
Mitsubishi UFJ Morgan Stanley Securities also warned of possible service disruption. Japan’s government said its information systems had been affected.
Some Japanese workers switched routine updates to fax machines, the Japan Times reported.
Microsoft Works to Stabilize Its Servers
Microsoft’s incident updates described servers unexpectedly becoming unavailable, leaving the remaining infrastructure under greater strain. Engineers rerouted traffic, restarted servers and tested changes to automated health checks. Some servers became unresponsive again when traffic returned.
On Friday morning, Microsoft reported improving server stability after applying a patch to an upstream authentication and routing component. It was extending the fix while also adjusting traffic flows. Recovery work was continuing, and the company said it had no indication that malicious activity caused the incident.
We’re seeing positive results for service stability and increased capacity as a result of our latest traffic optimization actions.
– Microsoft 365 Status (@MSFT365Status) November 13, 2026
A Reliability Test for Microsoft’s Cloud Business
The outage reaches a business that has been growing quickly. Microsoft’s latest earnings showed reported Microsoft 365 commercial cloud revenue rising 17%, while the broader Microsoft Cloud measure reached $63.9 billion for the September quarter.
The disruption also delayed corporate reporting. Workhorse Group moved its quarterly results from November 12 to November 16, citing the outage. Air India rerouted customer emails while keeping flight operations running. Microsoft said it would provide a fuller report after the incident was mitigated.
