# Iterable: Major incident: Email send delays for some US-hosted SparkPost traffic

**Summary:** Iterable reported a major degradation in Global Campaign Sends: US-hosted customers using SparkPost experienced email delays from elevated 5xx errors and Transmissions API latency. It started at 2026-02-24 19:51 UTC and resolved at 2026-02-24 19:52 UTC, lasting 1 minute. EU-hosted traffic and other ESPs were unaffected; SparkPost’s API issue was resolved. _(machine-written, sol)_
- Kind: Major incident · Label: degradation (model (Jev))
- Changed: 2026-02-24 19:51 UTC · Detected: 2026-10-17 18:22 UTC
- [Source: https://stspg.io/ry0mhjw7s6q3](https://stspg.io/ry0mhjw7s6q3)
- [Company: Iterable](https://rewindex.com/company/iterable.md)
- Versions: before (none: first archived) → after incident\_version:247/vrg56ts9ksvw@62c6185ddd94
- Change 1 of 1 for this incident

## What changed

**1. Added: Title**

```diff
+ Email send delays for some US-hosted SparkPost traffic
```

**2. Added: Impact**

```diff
+ major
```

**3. Added: Status**

```diff
+ resolved
```

**4. Added: Start time**

```diff
+ 2026-02-24 19:51 UTC
```

**5. Added: Resolved time**

```diff
+ 2026-02-24 19:52 UTC
```

**6. Added: Affected components**

```diff
+ Global Campaign Sends
```

**7. Added: Update** (monitoring) · 2026-02-24 19:51 UTC

```diff
+ Email sends for US-hosted customers using SparkPost were delayed due to elevated 5xx errors and increased API latency from SparkPost’s Transmissions API. EU-hosted traffic was not impacted.  All customers using ESPs other than Sparkpost were similarly not impacted. SparkPost has indicated the incident is resolved. We’re monitoring outbound email queues to ensure sends are fully processing as expected. If you continue to experience issues, please contact Support.
```

**8. Added: Update** (resolved) · 2026-02-24 19:52 UTC

```diff
+ SparkPost’s API issue has been resolved, and we’re no longer seeing elevated 5xx errors or increased latency. Incident has resolved.
```

## History of this incident

| When (UTC) | Change | Label |
| --- | --- | --- |
| 2026-02-24 19:51 UTC | Major incident: Email send delays for some US-hosted SparkPost traffic (this change) | degradation |

All Iterable changes: [timeline](https://rewindex.com/company/iterable/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/i681af4ed4194a3 · Markdown: https://rewindex.com/change/i681af4ed4194a3.md · JSON: https://rewindex.com/api/v1/changes/i681af4ed4194a3 · Generated 2026-10-18T05:15:45.081Z