Microsoft Outlook outage hits thousands as users struggle to access emails

MUMBAI: Email appears to be having a Monday meltdown. Thousands of Microsoft Outlook users across the US reported problems accessing their inboxes as Microsoft investigated an authentication issue affecting Exchange Online.

The disruption began at around 8am PT on August 31, with users reporting difficulties across both Outlook’s website and app. At about 8.17am PT, Downdetector recorded more than 6,000 reports of problems, indicating a sharp spike in outages.

Users reported a range of issues, including being unable to receive or send emails, open Outlook, access their accounts, search messages and retrieve incoming mail.

Microsoft acknowledged the incident through its official Microsoft 365 Status account on X, saying it had identified a problem with an authentication component that was contributing to the disruption.

The company said engineers had developed a remediation strategy and were testing the fix on part of its infrastructure. Microsoft planned to expand the rollout after confirming that the solution was successfully restoring service.

The incident is being tracked internally as EX1464935.

The problem appears to be linked to Exchange Online, the cloud-based email service that powers mailbox access and email delivery for Outlook and Microsoft 365 users.

As a result, the disruption can affect users even when the Outlook application itself is working normally. An authentication failure can prevent the application or website from establishing a successful connection with Microsoft’s services.

That can leave users unable to open their inbox, retrieve new messages or carry out basic email functions.

The outage has affected several parts of the Outlook experience. Reports have included difficulties with receiving emails, sending messages, using the Outlook app, accessing the web version, searching mail and opening the service altogether.

The concentration of reports across different parts of the US suggested that the issue was broader than an isolated account or regional problem.

Microsoft’s identification of an authentication issue in Exchange Online offered a likely explanation for the surge in user complaints.

Microsoft said it was initially applying its remediation to a portion of its infrastructure while engineers monitored the results. If the fix continued to work as expected, the company would expand its deployment.

This means service may return progressively rather than all affected users regaining access at the same time.

For users still unable to access their accounts, the disruption appears to be a Microsoft-side service issue rather than a problem with individual Outlook accounts. Repeatedly changing account settings is therefore unlikely to help while the underlying service is being restored.

The outage is another reminder that Outlook is closely tied to Microsoft’s cloud infrastructure. When Exchange Online stumbles, the effects can quickly ripple across sending, receiving and accessing email. For thousands of users, the inbox will have to wait until Microsoft’s fix finishes making its rounds.