Outlook Web can't reach the internet. Check your connection.

Microsoft is currently reporting a service degradation affecting Microsoft 365 and consumer services, so wait for the incident to be resolved and then select Retry in Outlook Web.^1^

Check the incident status

• Personal Outlook.com/Hotmail account: Monitor the public Microsoft Service Health Status page.
• Microsoft 365 work or school account: Ask an administrator to open Microsoft 365 admin center → Health → Service health, then select the active Exchange Online or Microsoft 365 incident for its status and updates. Service Support and Helpdesk administrators can also view this page.^2^
• When the status changes to Service restored, reload Outlook Web and select Retry. Repeated browser resets or account changes will not resolve an active Microsoft-side incident.

If Microsoft reports the service as restored

Determine whether the remaining problem is limited to the browser or local network:

1. Open Outlook in an InPrivate/Incognito window.
2. If it works there, clear cookies and site data for Microsoft/Outlook sites in the regular browser.
3. Temporarily disable ad blockers—particularly AdBlock or Ublock—and other privacy-filtering extensions. Microsoft documents that these can prevent Outlook.com from loading.^3^
4. Test the latest version of a supported browser:
   • Windows: Edge, Chrome, or Firefox
   • macOS: Edge, Chrome, Firefox, or Safari 16+
   • Linux: Chrome or Firefox
5. Try another device or switch temporarily from Wi-Fi/LAN to a mobile hotspot. If Outlook works on the hotspot, investigate the original network’s DNS, proxy, VPN, firewall, or web-filtering configuration.
6. If this is a managed work or school network, have the administrator check whether the proxy/firewall permits outbound HTTPS access to Microsoft 365 and Outlook endpoints. Microsoft’s connectivity guidance specifically includes *.outlook.com over TCP/HTTPS ports 80 and 443.^4^

If the public status is healthy but several users in the same organization remain affected, an administrator can select Report an issue from Health → Service health so Microsoft can assess the tenant-specific reports.^2^

References

1. Service Health Status - Microsoft
2. How to check Microsoft 365 service health
3. Supported browsers for Outlook on the web and Outlook.com | Microsoft Support
4. How to troubleshoot non-browser apps that can't sign in to Microsoft 365, Azure, or Intune | Microsoft Support