Live / Incidents / mailgun
mailgun: Microsoft Incident Resulting in Delivery Issues
mailgun · mailgun.comImpact: noneResolved2026-09-04 12:20 UTC
Public — what happened
Summary
Starting around 08:00 UTC, Microsoft began experiencing an incident causing an increased volume of deferred emails across all X regions. The affected responses are returning "451 4.7.500 Server busy". Our teams are actively monitoring the situation. No other email providers are currently affected.
Timeline
- Started — 2026-09-04 12:20 UTC
- Last update — 2026-09-04 12:20 UTC
- Resolved — 2026-09-04 13:00 UTC
With SquidGrid — where it starts on the route
Independent path health
The status page is the symptom. SquidGrid measures the paths that reach mailgun against their own baselines — whether the routes carrying your traffic degraded, at which handoff, and who owns that stretch.
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