Microsoft tests fix for latest hours-long Outlook outage

Microsoft is working to resolve a widespread, multi-hour outage affecting its Exchange Online service, which caused email delays and authentication failures for many users. The company identified an issue with an authentication component and is currently testing a fix.
Why it matters
The outage highlights the critical dependency of global business operations on cloud-hosted email and communication infrastructure.
Snow day? Microsoft on Monday confirmed a widespread, multi-hour outage affecting Outlook users, leading to email delays and failures, authentication issues, and other problems.
In a post on X , Microsoft reported the issue was impacting its Exchange Online service, its cloud-hosted platform for business email, calendar, contacts, and tasks, and then said it had identified the problem.
“We’ve confirmed that users may experience degraded functionality with various Exchange Online functionalities. We’re reviewing service telemetry and diagnostic data to isolate the source of the issue,” Microsoft wrote at 12:43 PM ET on Monday, after an earlier message saying it was investigating user reports of Exchange Online problems.
Get smarter about the news
Sign up free for a feed built around what you actually care about, Dive Deeper research on any story, and the full text of every article.
Create free accountAlready have an account? Sign in