Exchange Online outage delays emails as Microsoft investigates root cause
Microsoft is investigating an ongoing Exchange Online outage that is delaying emails to and from external domains and causing intermittent 'Server busy' errors. Anti-spam protections may be contributing to the impact, and a remediation timeline has not been provided. The incident is tracked as EX1467029, with Microsoft continuing telemetry analysis to determine the underlying cause. Previous outages in April and June are noted in context.