Microsoft Exchange Online is currently facing a significant issue where legitimate emails are being wrongly classified as phishing attempts, leading to their quarantine and obstructing communication flows. This incident, labeled as EX1227432, was first identified on February 5, 2026, at 10:31 AM EST and continues to affect users.
Impact on Exchange Online Users
The incident has been categorized as a service degradation impacting Microsoft Exchange Online. Users are encountering difficulties in sending and receiving emails as genuine messages are flagged as phishing due to stringent detection measures. This mishap is attributed to a new URL rule that inaccurately tags safe URLs as threats, resulting in the unnecessary quarantining of emails.
The mishandling of emails is affecting many users, who find their messages trapped in quarantine, thereby hampering the productivity of organizations dependent on the platform. Microsoft has not yet specified the extent of the impact, including the regions or the number of customers affected.
Ongoing Efforts to Resolve the Issue
Microsoft is actively working to rectify the situation by reviewing quarantined messages and unblocking legitimate URLs. Updates provided over the weekend indicate progress, with a full resolution expected soon, although an exact timeline remains unspecified. Administrators have reported the need for manual intervention to release emails, though some messages are now being delivered following Microsoft’s recent efforts.
Users are advised to keep an eye on the Microsoft 365 admin center for updates regarding the status of EX1227432. Microsoft continues to emphasize improvements to prevent future occurrences of such misidentifications.
Historical Context and Future Considerations
This incident is not an isolated case for Microsoft Exchange Online. The platform has previously encountered false positives; for instance, a machine learning model incorrectly flagged Gmail emails as spam in May 2025. Similar incidents occurred in March and September 2025, causing disruptions in email and Teams services.
The ongoing challenges highlight the delicate balance Microsoft must maintain between security and usability. As phishing tactics evolve, the company’s AI-driven solutions occasionally overreach. Organizations are encouraged to report false positives using quarantine tools and consider alternative filters to enhance redundancy.
Microsoft’s statement reiterates their dedication to refining their systems to prevent such issues, although a complete fix remains pending. Users are reminded to check quarantines regularly and adhere to the established policies.
Stay updated on cybersecurity developments by following our news on Google News, LinkedIn, and X. Reach out to us if you wish to share your stories.
