E-mail services is down

Microsoft has confirmed an active Microsoft 365 incident affecting Exchange Online and Outlook, but no firm estimated restoration time has been published.

The incident may prevent mailbox access through classic Outlook, Outlook on the web, Exchange ActiveSync, and REST-based connections. Email delivery may also be delayed. Other Microsoft 365 services that depend on Exchange data may be affected. ^1^

Check restoration progress

For a business account, ask your Microsoft 365 administrator to:

1. Sign in to the Microsoft 365 admin center.
2. Go to Health > Service health.
3. Under Active issues Microsoft is working on, open the Exchange Online/Outlook incident.
4. Review All updates, particularly the latest status, mitigation progress, and any subsequently published recovery estimate.
5. Optionally select Manage notifications for this issue to receive incident updates.

The dashboard provides tenant-specific impact and Microsoft’s ongoing investigation, mitigation, and restoration messages. Service Support admins and Helpdesk admins can also view service health. ^2^

If the admin center is inaccessible, use Microsoft’s public service-status page linked from that same documentation.

What to do now

• Avoid repeatedly reinstalling Outlook, recreating profiles, or changing account settings while the incident remains active.
• Do not repeatedly resend important messages; delayed messages could be delivered after service recovery.
• If your organization is not shown as affected in Service health, an administrator can select Report an issue from that page.
• After Microsoft marks the incident Service restored, restart classic Outlook and test sending and receiving. If only one user remains affected, the administrator can then investigate that mailbox separately.

When Exchange Online is shown as degraded, Microsoft advises monitoring Service health because engineers are already restoring the service; a separate support request is generally unnecessary for the same known incident. ^3^

References

1. Microsoft Admin Center Status
2. How to check Microsoft 365 service health
3. Find and fix email delivery issues as a Microsoft 365 for business admin