Microsoft customers regain email after 20-hour-plus outage

What went down and when

Service trouble kicked off just before 1 p.m. ET on Thursday and spread across Outlook email and calendar along with Microsoft 365 services like SharePoint and Copilot. The impact stretched through Friday's business hours in Asia, continued into the European morning, and lingered into the early U.S. day, affecting millions and a host of third party tools that plug into Microsoft's stack.

By around 9 a.m. ET Friday, Microsoft warned some users still might not connect to several Microsoft 365 products, including Outlook on the web or desktop and services that interact with email. The company also said it was seeing steady improvement, with queues falling back toward normal, and noted that Asia Pacific regions were among the first to stabilize.

What Microsoft changed to restore service

Engineering teams pulled affected systems out of rotation to apply fixes, then brought them back gradually. Microsoft announced at 4 p.m. ET Thursday that it had "validated an alternative service health check method," began a wider deployment of that approach, and used it to bring some affected servers back online. It also prepared automated recovery to detect and restart unresponsive servers to support stability while changes took effect.

Microsoft focused on preserving delayed emails and cutting backlogs, extending the delivery retry window to 48 hours so held messages would keep attempting to send. The company said it has seen no signs of malicious activity. Initial diagnostics pointed to a traffic spike in part of its infrastructure and a problem in a component that processes server health, compounded by an "elevated load across multiple regions" after some servers became unexpectedly unavailable. As a result, some machines did not pass automated health checks.

Who felt it and how leaders reacted

Authorities and companies across Asia Pacific and Europe said they were tracking the disruption. The U.K.'s National Health Service reported some services were affected but told patients to keep appointments. Posting on X, a hospital network serving South West London as well as the English county of Surrey warned that callers might encounter lengthy hold times because of the disruption.

Richemont slightly delayed its earnings on Friday. Workhorse Group, the electric truck maker, shifted its anticipated third quarter release from Nov. 12 to Nov. 16, attributing the change to business disruptions linked to the global Microsoft outage. To maintain receipt of customer messages, Air India said it "temporarily rerouted" emails and noted that flight operations were unaffected.

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Australia's Home Affairs and Cyber Security Minister Tony Burke said at a press conference that Microsoft "believe they are dealing in some ways similar to what we saw with respect to CrowdStrike where there is an update that has gone awry," according to Reuters. A flawed update from CrowdStrike triggered one of 2024's largest IT outages, hitting airlines and banks.

Speaking by phone, James Owen - the managing partner of Digital Risks at the consultancy Control Risks - called the episode a "resilience and dependency issue that has been decades in the making." He added that organizations are increasingly mindful, including through a geopolitical lens, of which technologies they adopt, and that the episode shows the value of recovery playbooks such as manual backups, offline protocols, diversified suppliers and rehearsed crisis plans.

The market angle and what to watch next

Microsoft said intermittent issues may continue as restoration proceeds. Meanwhile, users of Amazon Web Services and Google also filed outage reports on Thursday. Amazon posted on X that its services were "operating normally" and said an unrelated internet disruption was leading to inaccurate reports, directing customers to its health dashboard for official status. In premarket trading, Microsoft shares were down about 0.8 percent.

In plain English: this was a stress test of email and collaboration plumbing. In 2025, the company underscored how vast its ecosystem has become by stating that Copilot - a collection of AI helpers and utilities - topped 100 million monthly active users, which helps explain why the ripple effects were so wide.

For your portfolio, outages like this can delay disclosures, disrupt operations and ping sentiment. Watch for any postmortem from Microsoft on the traffic surge and server health component, plus any spillovers to customers. The bottom line: resilience planning is back in focus, and vendors with clear recovery muscle will have the edge.

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