Microsoft restores Exchange Online email service after global outage disrupted millions

Microsoft’s Exchange Online email services began recovering early Tuesday after a widespread outage disrupted access for millions of users worldwide, the company said.

The failure, which started Monday evening, blocked logins and halted the sending and receiving of messages for both Microsoft 365 business customers and Outlook personal users. Microsoft attributed the issue to a fault in a central authentication and connection component within Exchange Online’s cloud infrastructure, which prevented access to servers. Technicians deployed targeted fixes overnight, and telemetry data later showed a clear improvement, with traffic gradually returning to normal systems .

User reports on platforms like Downdetector surged into the tens of thousands during the peak of the disruption, though numbers declined as services stabilized. Microsoft cautioned that some users may still experience delays as backlogs in email delivery are cleared and global synchronization fully resumes .

Separately, European email security firm xorlab announced it had secured €5 million in a Series A+ funding round led by existing investor Spicehaus Partners, with participation from Grapha Holding, EquityPitcher Ventures and ZKB Start-up Finance. The capital will support the company’s expansion across Europe and the development of its behavioral AI-driven email security platform, which analyzes messages for anomalies such as unusual senders or payment requests to detect phishing and business email compromise attempts .

xorlab’s platform can be deployed on-premises, in hybrid configurations, or in European data centers, aligning with regulations like the Digital Operational Resilience Act, NIS2 and GDPR. The company counts financial institutions, healthcare providers and critical infrastructure operators among its clients, including Julius Bär, Swisscom, Vontobel, G+D and CERN. CEO and co-founder Antonio Barresi said the funding reflects growing demand for European-developed cybersecurity solutions as organizations seek to reduce reliance on U.S.-based providers .