# Klaviyo: Major incident: Flow Sending Delays

**Summary:** Klaviyo reported a major degradation in flow message sending starting 2026-10-17 17:01 UTC, with some customers’ flow emails delayed; immediate sends remained unaffected. The incident was still open when archived, after 1 h 4 min at the last update. Klaviyo said it had identified the cause and was working on a fix, without specifying either. _(machine-written, sol)_
- Kind: Major incident · Label: degradation (model (Jev))
- Changed: 2026-10-17 17:01 UTC · Detected: 2026-10-17 18:22 UTC
- [Source: https://stspg.io/lb022bww184p](https://stspg.io/lb022bww184p)
- [Company: Klaviyo](https://rewindex.com/company/klaviyo.md)
- Versions: before (none: first archived) → after incident\_version:249/h0nhg0mtrj77@4f9d5d470ef4
- Change 1 of 8 for this incident

## What changed

**1. Added: Title**

```diff
+ Flow Sending Delays
```

**2. Added: Impact**

```diff
+ major
```

**3. Added: Status**

```diff
+ identified
```

**4. Added: Start time**

```diff
+ 2026-10-17 17:01 UTC
```

**5. Added: Affected components**

```diff
+ Email Sending, Flow Editor, Flows - Email Sending, Flows - Flow Editor, Flows - Mobile Push Sending, Flows - Processing, Flows - Text Message Sending, Flows - WhatsApp Sending, Mobile Push Sending, Processing, Text Message Sending, WhatsApp Sending
```

**6. Added: Update** (investigating) · 2026-10-17 17:01 UTC

```diff
+ We are investigating reports of delays affecting flow message sending. Some customers may see flow messages send later than expected. Immediate sends are not affected and are going out as expected. We will share another update as soon as we have more information.
```

**7. Added: Update** (investigating) · 2026-10-17 17:31 UTC

```diff
+ We are continuing to investigate delays affecting some flow email sending. Immediate sends remain unaffected. We will share another update as soon as we have more information.
```

**8. Added: Update** (identified) · 2026-10-17 17:35 UTC

```diff
+ We have identified the cause of the delays affecting flow message sending and are working on a fix. Some customers may continue to see flow messages send later than expected while we resolve this. We will share another update shortly.
```

**9. Added: Update** (identified) · 2026-10-17 18:06 UTC

```diff
+ We are continuing to work on the fix for this issue. Some customers may continue to see flow emails send later than expected while we resolve this. Immediate sends remain unaffected. We will share another update shortly.
```

## History of this incident

| When (UTC) | Change | Label |
| --- | --- | --- |
| 2026-10-17 17:01 UTC | Major incident: Flow Sending Delays (this change) | degradation |
| 2026-10-17 18:33 UTC | [Incident updated: Flow Sending Delays](https://rewindex.com/change/r7e504705c663e8.md) | Normal progress |
| 2026-10-17 19:13 UTC | [Incident updated: Flow Sending Delays](https://rewindex.com/change/r20dcdf6ac277c7.md) | Normal progress |
| 2026-10-17 19:43 UTC | [Incident updated: Flow Sending Delays](https://rewindex.com/change/r02256c12541fc9.md) | Normal progress |
| 2026-10-17 20:23 UTC | [Incident updated: Flow Sending Delays](https://rewindex.com/change/r52d9dd933d3981.md) |  |
| 2026-10-17 21:03 UTC | [Incident updated: Flow Sending Delays](https://rewindex.com/change/rd8174d44b4a9cc.md) |  |
| 2026-10-17 21:43 UTC | [Incident updated: Flow Sending Delays](https://rewindex.com/change/r352c2e3b0eaa9f.md) |  |
| 2026-10-17 21:53 UTC | [Incident updated: Flow Sending Delays](https://rewindex.com/change/r2eb155cf528d4d.md) |  |

Next: [change](https://rewindex.com/change/r7e504705c663e8.md) · All Klaviyo changes: [timeline](https://rewindex.com/company/klaviyo/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/if6243f0673327b · Markdown: https://rewindex.com/change/if6243f0673327b.md · JSON: https://rewindex.com/api/v1/changes/if6243f0673327b · Generated 2026-10-17T22:08:10.543Z