Microsoft 365 Outage, November 2026: Cause and Recovery

On 12 November 2026 (UTC), the early hours of Friday 13 November in Japan, a global outage hit Microsoft 365. Outlook could not open mailboxes, email did not arrive or was delayed, Teams could not handle meeting schedules, and Copilot did not respond. The impact lasted for nearly a full day.

Microsoft says that, as of the morning of 14 November (Japan time), it has confirmed broad, stable recovery. However, the incident has not yet been declared "resolved". Based on Microsoft's official announcements, this article covers what happened, the cause, the latest status, and what companies should check.

What happened

According to Microsoft, the outage began at around 16:17 UTC on 12 November (around 1:17 on 13 November in Japan). First, in Exchange Online, users could not connect to their mailboxes from Outlook on the web, the Outlook desktop app, smartphone mail apps (Exchange ActiveSync) and others. Then, at around 18:26 UTC, it was changed to a wider incident (MO1550821), described as a possible inability to connect to multiple Microsoft 365 services.

According to international media reports, reports to the outage tracking site Downdetector exceeded 130,000 at their peak. In Japan, the outage covered the whole of Friday's working hours. Japan's Ministry of Economy, Trade and Industry (METI) advised on 13 November that emails might not have reached it and that urgent matters should be handled by phone, and announced it would take steps such as extending deadlines for tenders and public calls for applications.

Timeline (UTC)

Based on Microsoft's service health updates, its official X account (@MSFT365Status) and its status page (status.cloud.microsoft). Items that appear only in media reports are marked as such.

Note: Microsoft posts its updates in US time or UTC. This table uses UTC (Japan is UTC+9).

The cause: Microsoft's explanation

In the early hours of 14 November, Japan time (13 November UTC), Microsoft gave the following explanation, according to media reports.

• "This was a technical issue not related to cyber or AI / agents."
• "The incident was introduced by an issue during an earlier network capacity upgrade that surfaced following a recent network change."

Microsoft also apologised to users and businesses: "We are deeply sorry for the disruption this incident has caused you and your business."

Affected services

According to Microsoft, Exchange Online and features that exchange data with email were affected, while parts that do not depend on email kept working. The main ones are below.

Microsoft also listed Microsoft Graph (the API for working with email and calendars), Planner, To Do, Universal Print and some pages of the Microsoft 365 admin center. Azure was not included: as of the morning of 14 November (Japan time), the Azure status page showed no problems.

Latest status (as of 01:00 UTC, 14 November 2026)

• The status page still shows "Service degradation".
• Microsoft says stable recovery is continuing in affected environments and, given the scale of the impact, it is monitoring for longer.
• It plans to declare the incident resolved only after confirming that all email queued during the outage has been processed.
• It says the impact on related products has mostly cleared.
• Consumer services (Outlook.com, OneDrive and others) are also showing as healthy again.

Microsoft's next update is due by 02:30 UTC on 14 November. We will update this article when there is new information.

Five things companies should check

1. Check the status through official sources

   In the Microsoft 365 admin center, check MO1550821 and EX1550543 under "Service health". If the admin center won't open, the same information is on status.cloud.microsoft. Summary sites and social media sometimes give different times or causes.

2. Check whether email from around 13 November arrived

   Because the email timeout was extended to 48 hours, much of the delayed mail is still to arrive. Avoid resending the same email again and again. Once the outage is resolved, use "Message trace" in the Exchange admin center to check important emails, such as contracts, quotes and submissions with deadlines. It also helps to ask business partners to contact you another way if an email they expected has not arrived.

3. Check that security features worked

   DLP, sensitivity labels, Defender for Office 365 and Intune are on the list of affected services. Check whether any email or files passed through without being checked during the outage, and whether Intune compliance status is back to normal. If you temporarily removed labels to export from Power BI, put them back. If audit log search or eDiscovery was unavailable, record the period.

4. Watch out for phishing that exploits the outage

   After a major outage, fake emails and messages posing as "mailbox recovery" or "account re-verification" tend to spread. Microsoft's official updates on this outage do not ask users to open links or sign in again. An Outlook vulnerability is also being exploited this month, so please also see "Microsoft's November security updates".

5. Review your procedures for when email stops

   When email, calendars, chat, AI and security tools all depend on the same platform, an outage has a bigger impact. Decide in advance on other ways to communicate (phone, another chat tool, a backup copy of contact details), who informs staff, and alternatives for procedures with deadlines.

Prepared vs. unprepared

Let Digi Dinos help

Digi Dinos supports companies with DX, security, and system operations and maintenance. We are ISO 27001 certified and offer server and cloud operations and 24/7 monitoring (NOC). Our team works with you in Japanese.

• Outage procedures: we set out the ways to communicate, the order of checks and who is responsible when a cloud service goes down.
• Monitoring and operations: we watch over your servers and cloud and set up systems that spot problems early.
• Operations takeover: we can take over systems whose staff have left or that another company managed.

Frequently asked questions