Microsoft has issued a public apology to customers and partners after a worldwide outage disrupted Outlook, Teams, Copilot and several other services for more than a day.
The company said on Friday, November 13, that it was seeing broad recovery and stability across its platforms. It traced the problem to an issue introduced during an earlier network capacity upgrade, which came to the surface after a more recent network change.
Microsoft stressed that the incident was not the result of a cyberattack and had nothing to do with artificial intelligence agents.
A Network Change Exposed an Earlier Flaw
According to a report by The Financial Express, Microsoft said the root cause lay in a problem that had been introduced during a previous capacity upgrade to its network. That latent issue only became visible once a subsequent network change was made.
In a statement posted on X, the company said it was "deeply sorry for the disruption this incident has caused our customers and partners."
Microsoft said it had fixed the underlying issue and would publish a full post-incident report once its internal review is finished.
A Deliberately Slow Restoration
Rather than switching everything back on at once, Microsoft restored services in stages, checking stability at each step because of the volume of demand on its systems. The company acknowledged this approach took longer but said it helped ensure the recovery held.
Reuters reported that the disruption began on Thursday and lasted more than 24 hours, and that Microsoft had not yet given a timeline for full recovery at that point. Some customers and regions were still experiencing problems as work continued.
Downdetector logged more than 7.4 million outage reports worldwide, with submissions peaking at nearly 20,000 per minute, according to Reuters.
Exchange Online at the Centre of the Disruption
The outage hit features tied to Exchange Online, Microsoft's cloud-hosted email and calendar service. Applications that did not rely on Exchange Online continued to function normally.
Because so many workplace tools are built on top of that service, the effects rippled widely. OpenAI and Anthropic also reported problems with their Microsoft connectors, the integrations that link their AI products to Microsoft applications.
Airlines, Exchanges and Shippers Feel the Impact
In India, IndiGo and Akasa Air reported delays or disruptions to their email support and pointed passengers to other customer-service channels. Both carriers said their flight operations were not affected.
Air India said it had temporarily rerouted emails to stay in contact with passengers, and that it was still replying within its usual 24-hour window. Its flights and other communication channels operated normally.
Elsewhere, European exchange operator Euronext reported email difficulties, insurer Aviva switched to backup arrangements for its earnings calls, and shipping group Maersk warned customers that updates could be delayed.
Second Major Incident in Two Months
The outage comes shortly after an Azure cloud disruption in October, which also affected Microsoft's productivity software and a range of other businesses.
Back-to-back incidents of this scale are likely to sharpen scrutiny of how large cloud providers test and roll out infrastructure changes, particularly when a flaw can remain hidden until a later update triggers it.
What the Outage Means for Businesses Relying on the Cloud
The episode is a reminder that shared cloud infrastructure can link the fortunes of companies in otherwise unrelated sectors, from aviation to finance to logistics. When a core service like hosted email fails, the knock-on effects reach far beyond the provider itself.
For founders and IT leaders, the practical lessons are familiar but pressing: map dependencies on single providers, maintain backup communication channels, and rehearse fallback plans. Those that had alternatives ready, as several airlines and Aviva did, were able to limit the damage while Microsoft worked through its recovery.
Source: The Financial Express
