Thousands of Microsoft business customers reported problems accessing their email when they returned from the weekend, and on Monday afternoon, Microsoft acknowledged widespread issues 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 problem appears to be much more widespread. In a statement shared with X at 12:01 pm ET, Microsoft confirmed that the Exchange Online service had been discontinued. (Exchange Online is a cloud-based business service “offering email, calendar, contacts, and tasks.”) This Tweet is currently unavailable. It may be loading or may have been deleted. Additionally, a Microsoft spokesperson provided the following statement to Mashable via email: “We are aware of an issue affecting access to Exchange Online and certain other services. We know this is disruptive to customers and appreciate your patience as we work to restore services as quickly as possible.” On its official status page, Microsoft explained which other services were affected by the outage. The status page reported “Service Degradation” for Microsoft 365 Business or Enterprise, with the issues affecting services such as: Microsoft says the root cause of the outage is an “issue within a central authentication configuration used by multiple Microsoft 365 services” and the company is actively testing a remediation strategy. Mashable Light Speed Microsoft 365 administrators can see MO1465074 and/or EX1464935 for the latest updates on the outage, if they can access the Admin Center. Microsoft provided an update on the situation at 6:01 p.m. ET, writing that it “continues to review recent changes to the service to definitively confirm the source of the issue.” This Tweet is currently unavailable. It may be loading or may have been deleted. Microsoft has since offered more updates and implemented mitigation measures to help bring its services back online. At 10:01 p.m. ET, the company informed users that its “recovery efforts are ongoing” and that they should see email delivery gradually come back online. Still, Microsoft warned that its search function is still experiencing problems. “We are closely monitoring the health of the service environment amid our ongoing recovery work, and we are observing some sections of the affected infrastructure that are not accepting reapplied authentication components as easily as expected,” Microsoft wrote on the official status page. “Users can expect to see continued recovery in email delivery, while users can see residual impact on downstream and dependent scenarios, including search, across all affected services. We are working to identify whether additional actions are required to expedite full recovery.” At 11:52 p.m. ET, Microsoft reported that mailbox connectivity should return to normal, although it was still working on search functionality. The company also noted that backlogged mail queues may take a while to clear “due to the volume of messages previously queued.” UPDATE: September 1, 2026, 12:29 pm AEST This article has been edited to add updates from Microsoft. UPDATE: September 1, 2026, 2:02 pm AEST This article has been edited to add updates from Microsoft. Topics Applications and software Microsoft
