# Mailgun: Major incident: Sending errors in US

**Summary:** Mailgun reported a major incident causing sending errors in US regions, affecting API, Email Services - API, and Email Services - Outbound Delivery. It began at 2025-09-12 10:07 UTC and was resolved at 2025-09-12 15:21 UTC, lasting 5 h 14 min. A fix was implemented, and all systems were operating normally at resolution. _(machine-written, sol)_
- Kind: Major incident · Label: outage (model (Jev))
- Changed: 2025-09-12 10:07 UTC · Detected: 2026-10-17 18:22 UTC
- [Source: https://stspg.io/8jcggcjc48kz](https://stspg.io/8jcggcjc48kz)
- [Company: Mailgun](https://rewindex.com/company/mailgun.md)
- Versions: before (none: first archived) → after incident\_version:251/zqyxry16x7qb@694aaa764d2f
- Change 1 of 1 for this incident

## What changed

**1. Added: Title**

```diff
+ Sending errors in US
```

**2. Added: Impact**

```diff
+ major
```

**3. Added: Status**

```diff
+ resolved
```

**4. Added: Start time**

```diff
+ 2025-09-12 10:07 UTC
```

**5. Added: Resolved time**

```diff
+ 2025-09-12 15:21 UTC
```

**6. Added: Affected components**

```diff
+ API, Email Services - API, Email Services - Outbound Delivery
```

**7. Added: Update** (investigating) · 2025-09-12 10:07 UTC

```diff
+ We are currently investigating reports of sending errors in US regions.
```

**8. Added: Update** (investigating) · 2025-09-12 10:28 UTC

```diff
+ We are continuing to investigate this issue.
```

**9. Added: Update** (investigating) · 2025-09-12 10:49 UTC

```diff
+ We are continuing to investigate this issue.
```

**10. Added: Update** (investigating) · 2025-09-12 11:14 UTC

```diff
+ We are continuing to investigate this issue.
```

**11. Added: Update** (monitoring) · 2025-09-12 12:03 UTC

```diff
+ A fix has been implemented and we are monitoring the results.
```

**12. Added: Update** (identified) · 2025-09-12 12:57 UTC

```diff
+ We are continuing to work to stabilize things at this time. We have no ETA.
```

**13. Added: Update** (identified) · 2025-09-12 13:42 UTC

```diff
+ Error rates are normalizing as we continue to work to fix the issue.
```

**14. Added: Update** (monitoring) · 2025-09-12 13:57 UTC

```diff
+ A fix has been implemented and we are monitoring the results.
```

**15. Added: Update** (monitoring) · 2025-09-12 14:48 UTC

```diff
+ Systems have normalized, we are continuing to monitor for any issues.
```

**16. Added: Update** (resolved) · 2025-09-12 15:21 UTC

```diff
+ All systems are operating normally at this time. Our engineers continue to monitor our systems for any recurrence or new issues.
```

## History of this incident

| When (UTC) | Change | Label |
| --- | --- | --- |
| 2025-09-12 10:07 UTC | Major incident: Sending errors in US (this change) | outage |

All Mailgun changes: [timeline](https://rewindex.com/company/mailgun/changes.md)
_Diff excerpts are shown on normalized text: dates, counters and tokens appear as ‹date›, ‹count›, ‹tok›; noise-only edits are hidden. Rewindex shows the changed passages, not a copy of the page._


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Canonical: https://rewindex.com/change/i324c79f5257633 · Markdown: https://rewindex.com/change/i324c79f5257633.md · JSON: https://rewindex.com/api/v1/changes/i324c79f5257633 · Generated 2026-10-18T02:55:41.253Z