Microsoft Outlook users may sometimes experience problems while opening the Outlook app, signing in, sending or receiving emails, or connecting to Microsoft servers. You may see errors such as "Something went wrong," "Outlook can't reach this page," "ERR_TIMED_OUT," "NetworkError," "ServerError," or "HTTP Error 503 – Service Unavailable." In some cases, Outlook may get stuck on the message "Outlook is checking for an updated version and will finish opening when ready."
These problems can be caused by internet connectivity, corrupted app data, incorrect Windows settings, outdated software, or temporary Microsoft server outages. Recently reported Microsoft 365 incidents, including EX1550543 and MO155082, have also been associated with service disruptions. If you are facing any of these Outlook problems on Windows 11, follow the methods below to troubleshoot and fix them.
Common Microsoft Outlook Errors
Before trying the solutions, here are some common Outlook errors you may encounter:
Outlook is not opening or responding.
Something went wrong and Outlook couldn't set up your account.
Outlook can't reach this page.
outlook.office.com took too long to respond.
ERR_TIMED_OUT.
Couldn't send this message. There was a problem with this message. Try again later.
NetworkError and ServerError.
HTTP Error 503 – Service Unavailable.
451 4.3.2 Temporary server issue.
Failed to fetch / Connection timed out.
Outlook is checking for an updated version.
Something went wrong during sign-in.
Error codes: 0x80040115, 0x800ccc0f, 0x8004210A, 0x8004210B and 0x8004010F.
Try the following troubleshooting methods to resolve these issues.
Method 1: Use Outlook Classic or Outlook on the Web
If the New Outlook app is not opening or keeps showing errors, try accessing your emails using Outlook Classic or Outlook on the Web. This helps you determine whether the problem is limited to the New Outlook application or related to Microsoft's online services.
Option 1: Use Outlook Classic
If Outlook Classic is already installed on your Windows PC, you can use it as an alternative.
Open the Windows Start menu.
Search for Outlook (classic).
Open the application and sign in with your email account if required.
Check whether your inbox loads and whether you can send and receive emails.
If Outlook Classic works properly, you can temporarily continue using it until the New Outlook issue is resolved.
Option 2: Use Outlook on the Web
If Outlook Classic is also not working, try accessing your email through a web browser.
Open Google Chrome, Microsoft Edge or any other browser.
Visit https://outlook.office.com.
Sign in using your Microsoft or work email account.
Check whether your inbox opens and emails are working.
If Outlook on the Web also shows errors such as ERR_TIMED_OUT, HTTP 503 or ServerError, the issue may be related to Microsoft's servers or your internet connection rather than the desktop application.
Method 2: End Outlook Task and Restart Windows Explorer
Sometimes Outlook may continue running in the background even after you close its window. This can prevent the application from opening properly. You can fix this by ending the Outlook process through Task Manager and restarting Windows Explorer.
Press Ctrl + Shift + Esc to open Task Manager.
Under Processes, find Microsoft Outlook or Outlook.
Right-click it and select End task.
Now find Windows Explorer in the same Processes list.
Right-click Windows Explorer and select Restart.
Wait for your Windows desktop and taskbar to reload.
Try opening Outlook again.
This method refreshes the Outlook process and Windows desktop environment without restarting your entire PC.
Method 3: Turn Off and On Your Internet Connection
Outlook requires a stable internet connection to communicate with Microsoft servers. If your connection is unstable or temporarily disconnected, Outlook may show errors such as ERR_TIMED_OUT, Failed to fetch, Connection timed out or Outlook can't reach this page.
Follow these steps:
Turn off Wi-Fi on your Windows PC.
Wait for approximately 10–15 seconds.
Turn Wi-Fi back on and reconnect to your internet network.
If you are using an Ethernet connection, disconnect and reconnect the network cable.
Open Outlook and check whether it works.
You can also restart your Wi-Fi router if the problem continues.
Disable VPN or Proxy: If you are using a VPN or proxy connection, temporarily disable it and try opening Outlook again. Some VPN or proxy configurations may interfere with Microsoft's connection services.
Check Windows Date and Time: Incorrect date, time or regional settings can sometimes cause authentication and secure connection problems. To check them:
Open Windows Settings.
Go to Time & language → Date & time.
Enable Set time automatically and Set time zone automatically, if appropriate.
Click Sync now.
Go to Language & region and verify that your country or region is correct.
Now restart Outlook and check whether the issue is resolved.
Method 4: Repair or Reset the Outlook App
If Outlook is still not opening, you can repair or reset the application using Windows Settings. This is particularly useful when New Outlook has corrupted app files, damaged settings or other local application problems.
How to Repair Outlook
Press Windows + I to open Settings.
Select Apps → Installed apps.
Search for Outlook.
Click the three dots next to Outlook.
Select Advanced options.
Scroll down and click Terminate to close the application completely.
Click the Repair button and wait for Windows to complete the process.
Once finished, open Outlook and check whether it works.
How to Reset Outlook
If repairing the application doesn't solve the problem, try resetting it.
Open Settings → Apps → Installed apps.
Search for Outlook and click the three dots.
Select Advanced options.
Scroll down and click Reset.
Confirm the reset when prompted.
Restart Outlook and sign in to your email account again if required.
Important: Resetting Outlook may remove locally stored app settings and require you to sign in again. Your emails stored on Microsoft's servers are not deleted by resetting the app.
Method 5: Update Windows 11
Sometimes Outlook problems can occur because of outdated Windows components, compatibility issues or pending system updates. Therefore, make sure your Windows installation is up to date.
Follow these steps:
Open Windows Settings.
Click Windows Update.
Select Check for updates.
If updates are available, download and install them.
Restart your PC after the installation is complete.
Open Outlook and check whether the problem is fixed.
Also check Microsoft Store for available updates to New Outlook. Open Microsoft Store, go to Library, and select Get updates.
Method 6: Check Microsoft Outlook Server Status
If none of the above methods work, there may be a problem with Microsoft's online services. Sometimes Outlook stops working because of a temporary service disruption, server overload or maintenance activity.
For example, Microsoft 365 incidents EX1550543 and MO155082 have been referenced in connection with reported service disruptions.
When Microsoft experiences a server-side problem, you may encounter errors such as:
HTTP Error 503 – Service Unavailable.
451 4.3.2 Temporary server issue.
NetworkError or ServerError.
ERR_TIMED_OUT.
Outlook.com took too long to respond.
Couldn't send this message. There was a problem with this message. Try again later.
To check whether Microsoft is experiencing an outage:
Open your web browser.
Visit the official Microsoft 365 Service Health Status page: https://status.cloud.microsoft/.
Check whether Outlook or Exchange Online is showing a service incident.
Open the incident details to see which services and users are affected.
If Microsoft confirms an ongoing outage, wait for Microsoft to resolve the issue.
Important: If the problem is on Microsoft's server side, you cannot fix it by reinstalling Outlook, resetting Windows or changing your email settings. You need to wait until Microsoft restores the affected services.
Conclusion
These are some of the most useful troubleshooting methods to fix Microsoft Outlook errors on Windows 11. If New Outlook is not opening, first try Outlook Classic or Outlook on the Web. Then restart Outlook through Task Manager, check your internet connection, disable VPN, verify your Windows date and time, and repair or reset the Outlook application. If the problem continues, update Windows and check Microsoft's official service status page. If Microsoft is experiencing a server outage, wait for the official resolution before making unnecessary changes to your Outlook installation.
