Microsoft Outlook outage leaves thousands struggling to access their email

Credit: Corbin Davenport / How-To Geek Published Nov 12, 2026, 2:35 PM EST Jefferson Mangubat is an experienced technology journalist who has reported on consumer electronics, software updates and big stories in the industry. He's now a Reporter at How-To Geek, and has built a solid reputation for delivering accurate, accessible, and insightful tech journalism. Prior to that, he was a tech reporter for Neowin, where he extensively covered hardware developments from Apple and Google, in addition to digital trends and application updates. Sign in to your How-To Geek account Microsoft Outlook users have experienced widespread disruption on November 12, with hundreds of thousands reporting problems accessing Microsoft's email service. According to Downdetector reports, the outage was widespread and hit right in the middle of the workday, disrupting access to email and broader Microsoft 365 services. Users complained of trouble loading their inboxes, logging into their accounts, and sending or receiving messages, and the outage-tracking platform logged more than 100,000 reports just after 1 p.m. Some users reported problems with Microsoft’s desktop and mobile apps. Microsoft’s 365 Status account on X confirmed the outage, saying it was investigating. The issue was tied to Exchange Online, Microsoft’s cloud-based email service that powers Outlook and other Microsoft 365 services. Interestingly, the problem came up as users reported issues accessing Copilot. Microsoft discovered connectivity errors affecting some of the infrastructure used to receive and handle mailbox access requests. The incident was logged as EX1550543, and affected connection methods could include Outlook on the web, Messaging API (MAPI), Exchange ActiveSync (EAS), and the Representational State Transfer (REST) API. The disruption wasn’t confined to Outlook, either. Microsoft 365 and Teams also had service interruptions, the company said. Microsoft initially said the disruption was impacting Exchange Online users in the Americas, although reports on Reddit suggested the problems were being felt elsewhere too. Microsoft said it has been collecting networking logs to help troubleshoot the connectivity errors and determine the appropriate mitigation steps. The company said affected customers should check for updates in the Microsoft 365 admin center under incident EX1550543. Some users also faced issues accessing Microsoft's administrative portal during the outage. Microsoft’s initial reports hadn’t provided a confirmed timeline for full restoration or pinned down a definitive root cause. Instead, impacted customers should monitor Microsoft’s service announcements until the company provides a final incident update and not presume their inbox is back for good.