# Mailgun: Major incident: Elevated 401 errors in US Region

**Summary:** Mailgun reported a major incident affecting API and Email Services - API in the US region, where some requests incorrectly failed with 401 errors. It started at 2026-03-19 18:43 UTC and lasted 10 min, resolving at 2026-03-19 18:53 UTC after a fix was deployed and systems returned to normal. _(machine-written, sol)_
- Kind: Major incident · Label: outage (model (Jev))
- Changed: 2026-03-19 18:43 UTC · Detected: 2026-10-17 18:22 UTC
- [Source: https://stspg.io/64kxkfp1nmhb](https://stspg.io/64kxkfp1nmhb)
- [Company: Mailgun](https://rewindex.com/company/mailgun.md)
- Versions: before (none: first archived) → after incident\_version:251/8w4q85qhsmgt@f22961546c0e
- Change 1 of 1 for this incident

## What changed

**1. Added: Title**

```diff
+ Elevated 401 errors in US Region
```

**2. Added: Impact**

```diff
+ major
```

**3. Added: Status**

```diff
+ resolved
```

**4. Added: Start time**

```diff
+ 2026-03-19 18:43 UTC
```

**5. Added: Resolved time**

```diff
+ 2026-03-19 18:53 UTC
```

**6. Added: Affected components**

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

**7. Added: Update** (identified) · 2026-03-19 18:43 UTC

```diff
+ Some requests may be incorrectly failing with 401 error codes in our US region.
```

**8. Added: Update** (resolved) · 2026-03-19 18:53 UTC

```diff
+ A fix has been deployed and systems are back to normal.
```

## History of this incident

| When (UTC) | Change | Label |
| --- | --- | --- |
| 2026-03-19 18:43 UTC | Major incident: Elevated 401 errors in US Region (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._


---
Canonical: https://rewindex.com/change/i38dbf4997c92d8 · Markdown: https://rewindex.com/change/i38dbf4997c92d8.md · JSON: https://rewindex.com/api/v1/changes/i38dbf4997c92d8 · Generated 2026-10-18T02:31:40.529Z