Check Microsoft’s service-status page first because an Outlook incident may leave the mailbox continuously loading even though account sign-in succeeds.^1^
1. Check for an Outlook service incident
- Open the Microsoft service health status page.
- If Outlook shows Service degradation, Service interruption, or another active incident, wait for Microsoft to restore service and monitor that page for updates. Resetting your password or repeatedly signing in will not resolve an active service incident.
- If this is a work or school account, ask your Microsoft 365 administrator to open Microsoft 365 admin center → Health → Service health and review active Exchange Online or Office on the web incidents.^2^
2. If service status is healthy, disable content blockers
Microsoft documents that AdBlock and uBlock can cause Outlook.com messages to load slowly, time out, or remain stuck loading.^3^
- Open your browser’s Extensions or Add-ons menu.
- Temporarily disable ad blockers and pop-up blockers for Outlook.com.
- With AdBlock in Chrome, select AdBlock → Don’t run on pages on this domain.
- Refresh Outlook.com.
- If it now opens, keep Outlook.com excluded from that extension or remove the problematic extension.
- If you use Firefox, test with its add-ons disabled; Microsoft specifically documents Firefox add-ons as a possible cause of an inbox not loading.
Because you can authenticate successfully, use Outlook.com’s support route:
- In Outlook.com, select Help from the top menu.
- Enter a description such as “Mailbox remains loading after successful sign-in” and press Return.
- If the suggested answers do not resolve it, scroll to Still need help? and select Yes to submit a support request.^4^
Include the browser name, approximate time the problem began, whether extensions were disabled, and any displayed error code. Do not post account details or diagnostic identifiers publicly.
References
- Microsoft service health status
- How to check Microsoft 365 service health
- Fixes or workarounds for recent issues on Outlook.com | Microsoft Support
- How to get support for Outlook.com | Microsoft Support