Redmond, Washington, United States — Microsoft 365 problems disrupted Outlook email and some Teams functions on Thursday, November 12, as Microsoft worked into the evening to restore server capacity. The trouble centred on Exchange Online, the service behind many work and school mailboxes.
November 13 update: Outlook access is returning for some users. In a 7 a.m. Eastern update reported by The Verge, Microsoft said availability and email performance were improving in Europe and North America. Email may still arrive late as Microsoft clears the backlog, and the company had not yet confirmed full recovery.
In an 9:58 p.m. Eastern incident update reproduced by the University of Pennsylvania, Microsoft still listed the disruption as ongoing. Users could have trouble opening mailboxes or receive messages late. Teams features that depend on Exchange Online, including calendars and meeting scheduling, could also fail; other features could remain available.
Why the outage lasted
Microsoft said some servers became unavailable unexpectedly, leaving the remaining infrastructure under strain even though overall traffic had not increased. It brought some servers back and redirected traffic, but warned that some servers could stop responding again once requests reached them. Microsoft was limiting certain traffic while working to restore service.
Reuters reported that Downdetector logged about 138,000 Outlook problem reports around 1 p.m. Eastern, falling to about 34,500 by early evening. Those are reports submitted to an outage tracker, not a count of everyone affected.
The servers we returned to service can become unresponsive again once they receive traffic.
— Microsoft 365 Status (@MSFT365Status) November 12, 2026
ABC News Australia reports on the disruption.
The disruption reached beyond the inbox
Electric vehicle maker Workhorse Group moved its quarterly earnings call from November 12 to November 16, citing business disruptions from the Microsoft outage.
For the current status, check Microsoft’s service health page. Work and school administrators can look up MO1550821 and EX1550543 in the Microsoft 365 admin centre.
Related: Our coverage of the Microsoft data centre protest in Amsterdam.
