Microsoft Outlook Down Again? Users Report Fresh Problems a Day After Microsoft Declared Global Outage Over

Microsoft Outlook users reported new problems Sunday morning, a day after the company said it had fully restored service following one of its longest and most disruptive outages in years.

According to outage tracker Downdetector, reports started climbing around 5:05 a.m. ET Sunday. Users described trouble loading their inboxes, connecting to the service and getting messages.

Microsoft had not publicly acknowledged a new incident as of Sunday morning. The company's most recent public status update said the problem behind last week's disruption had been fixed.

"We have completed our efforts to address the underlying issue of the incident and restored service to the remaining impacted customers and regions," the Microsoft 365 Status account said on X early Saturday.

Microsoft has directed administrators to incident MO1550821 in the Microsoft 365 admin center for further updates.

Leftover Effects or a New Problem?

It's not yet clear whether Sunday's reports point to a new technical failure or lingering effects of last week's outage.

During the recovery, Microsoft warned that restoring access would not immediately fix everything. "Service access can recover before mail flow fully normalizes," the company said in one update on X.

Large backlogs of delayed email piled up while the system was down. Some users have reported messages arriving hours or even days late as that backlog clears, which could make the service look broken even when it is technically online.

Downdetector compiles user reports and does not confirm the cause or scale of an outage. Sunday's reports were far fewer than during the peak of last week's disruption.

A Global Outage That Lasted More Than a Day

The earlier outage began Thursday, when users across North America suddenly could not reach their inboxes, send email or sign in. It quickly spread to other Microsoft 365 services, including Teams, the AI assistant Copilot and SharePoint Online, affecting users around the world.

Microsoft's first fixes did not hold. The company said it had restarted affected servers, but some became unresponsive again once traffic returned.

"We found a core process on affected servers is becoming overwhelmed, causing capacity loss," Microsoft said on X as it worked to restore service.

The disruption continued into Friday across Europe and Asia before service gradually returned. Microsoft declared it fully resolved early Saturday, more than a day after it began.

Microsoft Apologizes

Microsoft has said the outage was caused by a technical problem, not a cyberattack. It traced the failure to an issue during an earlier network capacity upgrade that surfaced after a recent network change.

The company apologized to customers. "We are deeply sorry for the disruption this incident has caused our customers and partners," a Microsoft spokesperson told the Daily Caller News Foundation.

Microsoft has said it will publish a detailed incident report.

Wide-Ranging Fallout

The outage reached well beyond office inboxes. Microsoft says more than 430 million people use its Microsoft 365 apps.

Governments, hospitals, airlines, banks and courts in several countries reported disruptions. In Britain, the National Health Service fell back on alternative systems. Indian airlines Air India, IndiGo and Akasa Air reported problems with email support. In Germany, rail operator Deutsche Bahn said Outlook was experiencing "severe sluggishness," which significantly delayed its email.

In Washington, the House of Representatives was also affected. "We have seen improvements to Outlook's functionality this morning, but will continue to monitor the situation until all issues are resolved and full functionality is restored to all Microsoft applications," said Samantha Carter, a spokeswoman for the House Chief Administrative Officer.

Electric truck maker Workhorse Group delayed its quarterly earnings release after the disruption.

What Users Can Do

Users having trouble with Outlook on Sunday can try a few basic steps:

• Check the Microsoft 365 service status page or the Microsoft 365 Status account on X for official updates.
• Sign out and back in, or restart the Outlook app or browser.
• Try Outlook on the web if the desktop or mobile app is not working, or the reverse.
• Allow extra time for delayed messages. Emails sent during last week's outage may still be arriving as Microsoft clears the backlog.
• Check with senders before resending important messages, to avoid duplicates.

Business and enterprise users should follow incident updates in the Microsoft 365 admin center and check with their IT departments.

Questions About Reliability

The latest reports are likely to add to questions about how much businesses and governments depend on a handful of cloud providers.

Outlook and Microsoft 365 have suffered several notable outages in recent years, including a roughly daylong disruption in November 2024, a login failure in March 2025 that Microsoft blamed on a problematic code change, and a mailbox infrastructure problem in July 2025 that knocked Outlook offline for hours.

Last week's failure stands out for its length and global reach. Some estimates put its total cost to businesses in the billions of dollars.

Microsoft has not said whether affected customers will automatically get service credits. Business customers can usually request credits under their service agreements when availability falls below guaranteed levels.

For now, Microsoft maintains that the main problem behind last week's outage has been fixed. Whether Sunday's reports are leftover effects or a new problem may become clearer as the company posts further updates.