Microsoft 365 is suffering a widespread service outage affecting Outlook, Exchange Online, Teams and other cloud services. The disruption began on Thursday 12 November 2026 and was still continuing on Friday morning, more than 12 hours later.
Microsoft's public status account first described problems accessing Exchange Online mailboxes. It later said the issue could affect Microsoft 365 connectivity in any region. Microsoft identified the incident references as EX1550543 and MO1550821.
At 3:13am GMT on 13 November, Microsoft said changes intended to improve the service were not working as expected. It was looking at other ways to add capacity while traffic remained uneven. At 10:12am GMT, Microsoft had not publicly confirmed a full recovery.
What users may see
The exact symptoms vary, but affected users may be unable to:
- open an Exchange Online mailbox in Outlook;
- send or receive business email;
- connect reliably to Microsoft Teams;
- use some SharePoint, Copilot or other Microsoft 365 services; or
- reach the Microsoft 365 admin centre to read tenant-specific updates.
This is a Microsoft cloud-service incident, not evidence that every affected PC, Outlook profile or office network has developed a fault at the same time.
What to do before changing anything
If several people in the same business lost Microsoft 365 access together, check Microsoft's public service status page and the Microsoft 365 admin centre under Health > Service health. Administrators should follow EX1550543 and MO1550821 for updates relevant to their tenant.
Avoid deleting Outlook profiles, reinstalling Office, resetting every password or changing DNS records simply because email has stopped during this incident. Those changes are unlikely to repair a fault inside Microsoft's infrastructure and can create extra work after service returns.
Use a separate communication route for urgent messages. A phone call, SMS or a non-Microsoft service may be more dependable until Microsoft confirms recovery. Be careful with repeated sending: if an application appears stuck, sending the same message several times may produce duplicates when connectivity returns.
How to tell whether you also have a local problem
Once Microsoft reports recovery, close and reopen Outlook and Teams, then allow a few minutes for mail and calendars to catch up. Test Microsoft 365 in a web browser as well as the desktop application.
Further investigation is reasonable if one computer still fails while other users on the same Microsoft 365 tenant are working normally. The remaining fault could then involve cached credentials, an Outlook profile, Office installation, Windows networking or a local firewall rather than the wider outage.
PC Repairs Barnstaple can help small businesses check whether a continuing problem is local, repair Outlook or Office configuration faults, and restore access after the Microsoft service itself is stable. We cannot repair Microsoft's cloud platform, but we can avoid unnecessary changes and get affected computers working again when the wider incident clears.
Microsoft's status may change quickly. Check the official service-health information before acting on this article.