# Microsoft Incident Resulting in Delivery Issues to M365

- Provider: [Mailjet](https://down.guide/providers/mailjet)
- Confidence: Confirmed
- Impact: Operational
- lasted 32m
- started 2026-09-04 12:23 UTC
- id: DWN-e6dbd79a86
- Official page: https://stspg.io/mn9fk6lf3d6r

## Updates from Mailjet
### 2026-09-04 12:23 UTC: monitoring
Starting around 08:00 UTC, Microsoft began experiencing an incident causing an increased volume of deferred emails across all M365 regions. The affected responses are returning "451 4.7.500 Server busy". Our teams are actively monitoring the situation. Sending to other email providers is not affected.

### 2026-09-04 12:55 UTC: resolved
This incident has been resolved.

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