Microsoft Investigating New Exchange Online Outage Tracked as EX1464935 [Updated]

Microsoft has opened an active investigation (EX1464935) into an Exchange Online disruption that began on 31 August 2026, reporting user access and mail-flow problems; the service is listed as "Investigating" while engineers analyze mail-flow diagnostics and telemetry. Administrators are advised to monitor the Microsoft 365 Service Health Dashboard and check mail queues, delivery reports, and connectivity; the report mentions past, non-malicious incidents tied to DNS or third-party providers but provides no indicators of compromise.