Microsoft acknowledges widespread Exchange Online problems - Mashable
ET, Microsoft confirmed that service to Exchange Online had been disrupted. Microsoft provided an update on the situation at 6:01 p.m. AEST This article has been edited to add updates from Microsoft.
Thousands of Microsoft enterprise customers reported problems accessing their email as they returned from the weekend, and on Monday afternoon, Microsoft acknowledged widespread problems affecting Exchange Online and other Microsoft 365 business services.
Initially, users took to social media and platforms like DownDetector to report problems with Microsoft Outlook, the widely used email service. However, the issue appears to be much more widespread. In a statement shared to X at 12:01 p.m. ET, Microsoft confirmed that service to Exchange Online had been disrupted. (Exchange Online is a cloud-based enterprise service "that delivers email, calendar, contacts, and tasks.")
In addition, a Microsoft spokesperson provided the following statement to Mashable via email: "We're aware of an issue affecting access to Exchange Online and some other services. We know this is disruptive for customers and we appreciate their patience while we work to restore services as quickly as possible."
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On its official status page, Microsoft elaborated on what other services were impacted by the outage. The status page reported "Service degradation" for Microsoft 365 Business or Enterprise, with the problems affecting services such as:
Microsoft says the root cause of the outage is an "issue within a core authentication configuration used by multiple Microsoft 365 services," and the company is actively testing a remediation strategy.
Microsoft 365 admins can see MO1465074 and/or EX1464935 for the latest updates on the disruption — if they can access the Admin Center.
Microsoft provided an update on the situation at 6:01 p.m. ET, writing that it's "continuing to review recent changes to the service to definitively confirm the source of the problem."
Microsoft has since offered further updates, having deployed mitigation measures to help bring its services back online. At 10:01 p.m. ET, the company advised users that its "recovery efforts are ongoing," and that they should see email delivery gradually come back online. Even so, Microsoft warned that its search feature is still experiencing issues.
"We're closely monitoring the health of the service environment amidst our ongoing recovery work, and we're observing some sections of affected infrastructure which aren't accepting the re-applied authentication components as readily as expected," Microsoft wrote on official status page. "Users can expect to see continued recovery to email delivery, while users may see residual impact to downstream and dependent scenarios, including search, across affected services. We're working to identify whether any additional actions are required to expedite full recovery."
At 11:52 p.m. ET, Microsoft reported that mailbox connectivity should now be back to normal, though it was still working on search functionality. The company also noted that it may take a while for backlogged mail queues to clear "due to the volume of previously queued messages."
UPDATE: Sep. 1, 2026, 12:29 p.m. AEST This article has been edited to add updates from Microsoft.
UPDATE: Sep. 1, 2026, 2:02 p.m. AEST This article has been edited to add updates from Microsoft.
Topics Apps & Software Microsoft
Timothy Beck Werth is the Tech Editor at Mashable, where he leads coverage and assignments for the Tech and Shopping verticals. Tim has over 15 years of experience as a journalist and editor, and he has particular experience covering and testing consumer technology, smart home gadgets, and men’s grooming and style products. Previously, he was the Managing Editor and then Site Director of SPY.com, a men's product review and lifestyle website. As a writer for GQ, he covered everything from bull-riding competitions to the best Legos for adults, and he’s also contributed to publications such as The Daily Beast, Gear Patrol, and The Awl.
Tim studied print journalism at the University of Southern California. He currently splits his time between Brooklyn, NY and Charleston, SC. He's currently working on his second novel, a science-fiction book.