A global Microsoft 365 outage that knocked Outlook, Teams and Copilot offline on Thursday stretched into a second day on Friday, November 13, 2026, with Microsoft reporting only "early stabilization and capacity improvements" and no firm time for full recovery. The Microsoft 365 outage has now disrupted email and workplace tools for tens of thousands of people in 74 countries, and Microsoft has extended its email timeout to 48 hours to preserve messages caught in the backlog.

US News Pulse first reported the outage on Thursday, when failed-inbox reports surged just after noon Eastern time and peaked at roughly 130,000. By Friday morning, about 15,000 Outlook problem reports were still coming in — a sign the failure was easing but far from over.

Key Points

• The outage began Thursday, November 12, 2026, and was still not fully fixed on Friday, November 13, stretching into a second day.
• Outlook, Teams, Copilot and SharePoint are affected, with Exchange Online hit hardest.
• Downdetector reports for Outlook peaked at about 130,000 shortly after 1 p.m. ET on Thursday, with 74 countries affected.
• Microsoft blamed servers that unexpectedly became unavailable after failing automated health checks, and said it is "not aware of any malicious activity".
• The incident is tracked as EX1550543 for Exchange Online and MO1550821 for Microsoft 365, and the email timeout is extended to 48 hours.

Microsoft 365 Outage: What Happened on Day Two

On Friday, Microsoft said it was seeing "early stabilization and capacity improvements", but gave no time for full recovery and warned capacity had not fully returned to baseline: the worst had passed, yet the system was still fragile.

Microsoft also warned that servers returned to service could become unresponsive again once traffic reached them, which is why recovery has been gradual. Engineers are bringing capacity back in stages, redirecting traffic and restarting affected servers, rather than switching everything on at once.

To protect mail caught in the disruption, Microsoft extended the email timeout to 48 hours, giving delayed messages two full days to arrive instead of bouncing back. For workers waiting on contracts, invoices and job offers, that is the difference between a late email and a lost one.

Teams is a mixed picture. Calls and chats mostly work, but calendar and scheduling tasks may fail, so meetings booked through the app can vanish or refuse to save. SharePoint and other Exchange Online-dependent features remain hit hardest, with some users still unable to open mailboxes in Outlook on the web or desktop.

How the Outage Began on Thursday

The failure struck mid-workday. Reports surged just after noon ET on Thursday, peaking at about 130,000 Outlook problem reports shortly after 1 p.m. ET. Microsoft 365 reports topped 46,000 and Teams reports reached about 3,000. Within about an hour, reports were coming from 74 countries and territories, and nearly 30 percent of early-evening reports came from outside the United States.

Microsoft logged the Exchange Online incident, EX1550543, at 16:17 UTC on Thursday, and the wider Microsoft 365 advisory, MO1550821, about two hours later. The company said a number of servers unexpectedly became unavailable and failed automatic health checks, straining the remaining infrastructure.

By about 6 p.m. ET, Microsoft said it was returning a portion of affected servers to service, and reports had fallen to about 32,500 for Outlook and 11,300 for Microsoft 365. But tens of thousands of reports continued into the evening, with more than 24,000 Outlook users still reporting problems around 10 p.m. ET.

What Caused the Failure

According to Microsoft, the disruption stemmed from an internal infrastructure failure, not an attack. Automated server health checks failed and triggered a cascading drop in cloud capacity, with the load coming from lost server capacity rather than extra customer traffic. The company said it had no indication of a cyberattack, and executive vice president Charles Lamanna confirmed no security breach was involved.

Microsoft has promised a full root cause in a post-incident report once the service is stable. Until then, the picture is of a routine safeguard going wrong: health checks meant to pull sick servers out of rotation took too many offline at once.

The incident is the third major Microsoft 365 disruption this year, after multi-hour outages in January and a code-update failure in August — a record Microsoft will have to explain in its post-incident report.

Reactions: Businesses Feel the Disruption

The outage has reached well beyond office inboxes. Electric truck maker Workhorse Group rescheduled its third-quarter results to November 16, citing the disruption. Hospitals, police departments and businesses were among those affected.

The failure also broke connectors used by OpenAI and Anthropic AI services, a reminder of how deeply Microsoft's cloud is woven into other companies' products. When Exchange Online falters, the damage spreads to tools that never mention Microsoft, including Google's Gemini 4 Hydrogen.

Why It Matters

Email remains the backbone of offices, schools and government agencies, and Outlook is the inbox most American workplaces run on. When it fails for two days, the cost is thousands of small delays: a contract unsigned, a medical result unread, a job application unanswered.

With users in 74 countries affected, this was not a regional glitch but a failure of the central infrastructure Microsoft sells as always available. Businesses pay for Microsoft 365 because they expect the cloud to absorb failures that would cripple a single office server — and on Thursday that promise broke.

What Happens Next

Microsoft will keep restoring servers and capacity in stages while monitoring for renewed instability. Users should expect intermittent problems, including delayed mail and Teams calendar failures, until Microsoft confirms capacity has fully returned to baseline.

Anyone waiting on an important message should check their inbox directly rather than relying on notifications; delayed mail is held for 48 hours rather than returned. Businesses that depend on Exchange Online connectors, including AI tools, should verify those links work again before relying on them.

The fuller account will come in Microsoft's post-incident report, which should explain why the health checks failed and how the company will stop it happening a fourth time. Until then, the second day of this outage shows even the largest clouds can go dark.

Frequently Asked Questions

Is Microsoft 365 still down?
Not entirely. Microsoft reported early stabilization on Friday, November 13, 2026, but capacity had not fully returned to baseline, with about 15,000 Outlook problem reports still coming in on Friday morning.

Which services are affected?
Outlook, Teams, Copilot and SharePoint are affected, with Exchange Online features hit hardest. Some users cannot open mailboxes in Outlook, email may be delayed, and Teams calendar tasks may fail.

Was the outage a cyberattack?
No, according to Microsoft, which said it is "not aware of any malicious activity" and confirmed no security breach. It blamed servers that unexpectedly became unavailable after failing automated health checks.

Will my delayed emails arrive?
Microsoft extended the email timeout to 48 hours, so delayed mail should still arrive rather than bounce back, though delivery may be slow until capacity is restored.

What are EX1550543 and MO1550821?
Microsoft's tracking numbers: EX1550543 covers the Exchange Online mailbox failure, logged at 16:17 UTC on Thursday, and MO1550821 covers the wider Microsoft 365 disruption logged two hours later.