Microsoft 365 outage disrupting Outlook and Teams enters second day

A widespread outage of Microsoft's cloud productivity services that began on Thursday, 12 November 2026, continued into Friday, disrupting email, calendars and other features for business customers in several regions. Microsoft said it was seeing partial recovery but had given no time for full restoration, according to reports from BleepingComputer, UC Today and ITdaily. Figures and status below are as reported up to about 12:30 GMT on Friday.

What happened

Problems began with Exchange Online, the service behind business Outlook mailboxes. UC Today reported that Microsoft opened an Exchange incident, EX1550543, at 16:17 GMT on Thursday. A broader Microsoft 365 incident, MO1550821, followed at 18:26 GMT, according to UC Today and BleepingComputer.

BleepingComputer reported that Microsoft's advisory said customers might be unable to connect to Exchange Online, Microsoft Teams, SharePoint Online, Microsoft 365 Copilot and Microsoft Defender XDR, and that Microsoft later said users in any region could be affected. ITdaily reported that the outage-tracking site Downdetector logged more than 130,000 Outlook problem reports on Thursday evening.

UC Today reported that joining Teams calls and meetings largely kept working, while calendar scheduling, meeting invitations, some Copilot features and other Exchange-dependent functions failed. Both UC Today and ITdaily reported that OpenAI and Anthropic said their Microsoft 365 connectors were affected.

UC Today reported that organisations affected in the UK included NHS England, where it said some staff reverted to paper records, as well as the Bank of England and the Financial Conduct Authority.

Cause

Microsoft has not confirmed a root cause. According to BleepingComputer, Microsoft said the elevated load on its systems "isn't driven by an increase in traffic" but by servers that had become unexpectedly unavailable, putting strain on the remaining infrastructure. UC Today and ITdaily reported that Microsoft said a process that sets up secure connections on affected servers had become overwhelmed, and that it began reverting a recent network configuration change that coincided with the start of the problems.

Microsoft said there was no indication of malicious activity, according to ITdaily and UC Today. ITdaily reported that Charles Lamanna, a Microsoft executive vice president, wrote on X: "We regret that today's outages caused disruption for our customers, and we are working to resolve the problem."

Recovery

On Friday morning Microsoft reported "early signs of stabilization" after applying a configuration patch and restarting affected infrastructure in stages, UC Today reported. By late morning GMT, recovery actions had been completed in parts of the Asia-Pacific region and were being extended to other regions, according to UC Today and ITdaily.

Microsoft said service health remained variable and that capacity had "not yet fully returned to baseline", UC Today reported. Both outlets reported that Microsoft extended its email delivery time-out to 48 hours so that delayed messages would not be lost. UC Today reported that Microsoft has promised a post-incident report.