Workers trying to log in to Microsoft Outlook ran into unexpected problems Monday morning, with some users seeing error messages and being signed out without warning as they started the workweek. Microsoft confirmed that some Microsoft 365 Business and Enterprise customers were experiencing a service interruption.
Some customers were unable to log in to the email software at all. Microsoft said some users may experience intermittent sign-in failures, including too many requests errors or unexpected sign-outs, and said it was analyzing service telemetry further to identify potential next steps and mitigation actions.
The outage was already showing up before many offices opened. Around 5 a.m. ET on Monday, DownDetector reported a spike in user error reports, and a majority of those users identified login issues as the problem. Microsoft Outlook error reports kept climbing as U.S. workers began their day, while Microsoft users on X said they were still unable to access Outlook.
By around 9:35 a.m. ET, the Microsoft 365 Status X account said the issues were ongoing. Microsoft’s service status page directed users to X for more information, while the Microsoft 365 support profile on X pointed them back to the website status page, leaving customers with two places to check and no clear fix yet. The email service also went down in January, adding to a pattern of interruptions that has now returned less than four months later.
The latest update, posted Apr. 27, 2026, 11:21 a.m. EDT, said the outage was still ongoing as of that writing. For now, the question for users is not whether Outlook is having problems — it is how long Microsoft will need to restore reliable sign-ins for the people who are locked out of their inboxes right now.
