Outlook not working

A Microsoft 365 administrator should check Admin center → Health → Service health → Exchange Online; the active incident’s updates are the authoritative place to find Microsoft’s current restoration status and any estimated recovery time.^1^

No reliable restoration time can be confirmed externally for your company’s tenant.

Check the incident and recovery estimate

1. Sign in to the Microsoft 365 admin center with an account assigned an appropriate admin role.
2. Select Health → Service health.
3. Under Active issues Microsoft is working on, open any incident affecting:
   • Exchange Online
   • Outlook on the web
   • Mailbox access or message delivery
4. Review:
   • Status
   • User Impact
   • Last updated
   • All Updates

Microsoft posts investigation progress, mitigation work, and confirmation of restoration there. A status of Restoring service means corrective action is being applied; Extended recovery means recovery may take time to reach every affected system.^1^

If the admin center itself is unavailable, use Microsoft’s public service status page linked from the same documentation.^1^

If Microsoft lists an active incident

Avoid changing Outlook profiles, licenses, DNS, or tenant settings unless the incident notice specifically instructs you to do so. Monitor All Updates for the next-update time and recovery estimate.

An administrator can also open the incident and select Manage notifications for this issue to receive status updates by email.^1^

If no incident appears

Because the entire company is affected, report it from the Service health page:

1. Select Report an issue.
2. Identify Exchange Online/Outlook on the web.
3. Include the approximate start time, affected-user count, regions, exact errors, and whether sending, receiving, and sign-in all fail.

Microsoft correlates these reports across organizations and adds an incident or advisory when it identifies a service-side problem.^1^

For immediate escalation, an administrator can select Help & support in the admin center, enter the outage details, and then choose Contact Support. If all subscriptions were purchased through a Microsoft partner, contact that partner instead.^2^

References

1. How to check Microsoft 365 service health
2. Get support for Microsoft 365 for business