Is Microsoft Outlook Down Today?

Microsoft Outlook was affected by a widespread Microsoft 365 service incident that began on August 31, 2026. The main affected service was Exchange Online, Microsoft's cloud-based email platform used by Outlook and many Microsoft 365 customers.

Microsoft's incident information reported problems including delays or failures when sending and receiving email, authentication-related errors, mailbox access problems and degraded functionality. Microsoft later reported that recovery was progressing across affected infrastructure.

Because Microsoft 365 service status can change quickly, an Outlook problem on your computer does not necessarily mean that Outlook is still experiencing a global outage. Always check the latest Microsoft service-health information before making major changes to your Outlook installation.

Reports published during the incident indicated that Outlook mail flow was recovering while Microsoft continued monitoring other affected Microsoft 365 workloads.

What Happened to Microsoft Outlook?

The disruption began on August 31, 2026, when Microsoft investigated widespread Exchange Online problems.

Microsoft later identified an issue within a core authentication configuration used by multiple Microsoft 365 services. Because Exchange Online and other Microsoft services depend on authentication infrastructure, problems with that component could affect users across several workloads.

Users reported problems accessing email, sending and receiving messages and authenticating with Microsoft 365 services. Search and other dependent functionality could also experience delays while Microsoft's recovery work continued.

This means that some Outlook problems during the incident were not caused by a user's Windows computer, internet connection or Outlook installation. They were related to Microsoft's cloud services.

What Problems Did Outlook Users Experience?

Depending on the account and service affected, users could experience several different symptoms.

• Outlook would not connect to the mailbox.
• Emails could not be sent.
• Incoming emails were delayed.
• Messages became stuck in the Outbox.
• Users experienced Microsoft 365 authentication errors.
• Previously received messages could be difficult to access.
• Outlook search could return incomplete or delayed results.
• Other Microsoft 365 services could also experience problems.

Microsoft's incident information specifically listed email delays or failures, authentication-related errors and difficulties with Exchange Online functionality among the affected scenarios.

Is Microsoft Outlook Working Again?

Microsoft reported improving service availability as mitigation actions progressed. Mail flow and core Exchange Online functionality recovered as the company continued monitoring the remaining affected infrastructure.

However, recovery from a large cloud-service incident can happen gradually rather than simultaneously for every customer, region and Microsoft 365 workload.

If Outlook is still not working for you, check Microsoft's current service status before assuming your local Outlook installation is damaged.

During the recovery period, Microsoft also monitored residual effects involving other Microsoft 365 services.

How to Check If Microsoft Outlook Is Down

1. Check Microsoft 365 Service Health

Microsoft 365 business and enterprise customers can check the Service Health section of the Microsoft 365 admin center for active incidents and service advisories.

If Microsoft has an active Exchange Online incident, local troubleshooting may not solve the problem until Microsoft's service has recovered.

2. Try Outlook on the Web

Try accessing Outlook through your web browser.

If Outlook fails both in the desktop application and on the web, the problem may be account-related or connected to Microsoft's online services rather than your local Windows installation.

3. Check Other Microsoft Services

Try another Microsoft 365 service such as Teams, OneDrive or SharePoint.

If several Microsoft services are experiencing problems simultaneously, a wider Microsoft 365 incident is more likely.

4. Check Your Internet Connection

Open several other websites in your browser. If other websites work normally but Outlook does not, continue with Outlook-specific troubleshooting and check Microsoft's service status.

How to Fix Microsoft Outlook Not Working

If Microsoft services are operating normally, try the following steps on your Windows PC.

Fix 1: Restart Outlook

Close Outlook completely and reopen it.

If Outlook is frozen, press Ctrl + Shift + Esc to open Task Manager. Find Outlook in the process list, end the task and then start Outlook again.

Fix 2: Restart Windows

A Windows restart can clear temporary processes and connection problems that may interfere with Outlook.

Fix 3: Check Your Internet Connection

Make sure your Windows computer has a stable internet connection. Try another website or service to confirm that your connection is working.

Fix 4: Update Microsoft Office

Older Office installations can contain bugs that have already been corrected in newer updates.

In supported Office installations, open an Office application and select:

File → Account → Update Options → Update Now

Install any available updates and restart your computer afterward.

Fix 5: Start Classic Outlook in Safe Mode

If you use Classic Outlook and the application keeps crashing or freezing, Safe Mode can help determine whether an add-in is responsible.

Press Windows + R, type:

outlook /safe

and press Enter.

If Outlook works normally in Safe Mode, an add-in may be causing the problem.

Fix 6: Disable Outlook Add-ins

Temporarily disable unnecessary Outlook add-ins and restart the application.

If Outlook starts working normally after disabling an add-in, re-enable add-ins one at a time to identify the problematic one.

Fix 7: Repair Microsoft Office

If Outlook continues to crash, freeze or fail to operate correctly, Windows provides repair options for Microsoft Office installations.

Go to:

Settings → Apps → Installed apps → Microsoft 365 or Microsoft Office → Modify

Depending on your installation, you may see options such as Quick Repair and Online Repair.

Outlook Not Sending or Receiving Emails?

If Outlook opens normally but email is not moving in or out of your mailbox, first determine whether Microsoft is experiencing an Exchange Online problem.

1. Open Outlook.
2. Check the Outbox.
3. Look for messages that are stuck or waiting to send.
4. Check your internet connection.
5. Check whether Outlook shows a disconnected status.
6. Try Outlook on the web.
7. Check Microsoft 365 service health.

If Microsoft has an active Exchange Online incident, waiting for service recovery may be necessary. Microsoft's incident information specifically reported email sending and receiving delays or failures during the August 31 event.

Why Is Outlook Search Not Working?

Outlook search can be affected by several different issues, including indexing problems, software problems and Microsoft service incidents.

During the September 2026 Microsoft 365 incident, search functionality was among the areas affected while Microsoft worked through recovery.

If Microsoft's services are operating normally and Outlook search still does not work, restart Outlook and Windows, install available Office updates and then investigate local indexing or profile problems.

Microsoft's incident reporting indicated that recovery included monitoring search functionality and other affected scenarios.

Should You Reinstall Outlook?

Usually, no—not as your first step.

If Microsoft is experiencing a server-side outage, reinstalling Outlook will not repair Microsoft's cloud infrastructure.

Before reinstalling Outlook, check:

• Microsoft 365 service status.
• Whether Outlook on the web works.
• Your internet connection.
• Whether other Microsoft 365 services are affected.
• Whether Office has available updates.

Only move to more advanced local troubleshooting after you have ruled out a Microsoft service incident.

Does an Outlook Outage Affect Office 2024?

Not necessarily.

Office 2024 is a one-time-purchase Office product rather than the Microsoft 365 subscription service. However, Outlook and other applications can still connect to online services when you use an internet-based account.

This means that an Office application installed on your Windows PC can continue to launch even when an online Microsoft email service is experiencing an outage.

If you are looking for Office 2024 products, see:

• Microsoft Office 2024 Professional Plus
• Microsoft Office 2024 Home & Business

Windows 11 and Microsoft Office Troubleshooting

Keeping Windows and Office updated is an important part of maintaining a reliable Windows PC.

If you are using Windows 11, you can explore the following Windows options:

• Windows 11 Pro License
• Windows 11 Home License
• Microsoft Windows 11 Pro License

Windows 11 Pro includes additional features designed for professional users, businesses and advanced Windows environments.

Microsoft Outlook Down Today: Quick Checklist

If Outlook suddenly stops working, use this quick checklist:

1. Check Microsoft service health.
2. Try Outlook on the web.
3. Check your internet connection.
4. Restart Outlook.
5. Restart Windows.
6. Check the Outlook Outbox.
7. Install Office updates.
8. Test Classic Outlook in Safe Mode.
9. Disable problematic add-ins.
10. Repair Office if necessary.

If multiple people are experiencing the same Outlook problem at the same time, particularly across different devices or networks, check for a Microsoft service incident before making significant changes to your computer.

Frequently Asked Questions

Final Thoughts

The September 2026 Microsoft Outlook and Microsoft 365 disruption shows why it is important to identify the source of an Outlook problem before attempting complicated repairs.

If Outlook suddenly stops sending or receiving email, first check Microsoft's service status and test Outlook on the web. If Microsoft is experiencing an outage, the correct solution may simply be to wait for Microsoft's recovery process.

If Microsoft's services are operating normally, work through the local troubleshooting steps: restart Outlook, check your connection, install Office updates, test Safe Mode, disable problematic add-ins and repair Office if necessary.

For Windows users who want to maintain an up-to-date PC and use current Microsoft software, choosing the appropriate Windows and Office edition is also important.

Sources and Further Reading

• Microsoft Support — Issues sending and receiving email
• Microsoft Learn — Fix Outlook connection problems in Microsoft 365