# Klaviyo: Flow Sending Delays

- Impact (vendor’s label): major
- Status: resolved · edited after publishing
- Started: 2026-10-17 17:01 UTC · Resolved: 2026-10-17 21:51 UTC · Duration: 4.8 h
- Updates: 11 · Affected components: Email Sending, Flows - Email Sending, Flows - Processing, Processing, Flows - Text Message Sending, Text Message Sending, Flows - Mobile Push Sending, Mobile Push Sending, Flow Editor, Flows - Flow Editor, Flows - WhatsApp Sending, WhatsApp Sending
- [Vendor status page: https://stspg.io/lb022bww184p](https://stspg.io/lb022bww184p)
- [Company: Klaviyo](https://rewindex.com/company/klaviyo.md)

## 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)_
## Timeline of updates

- **investigating** 2026-10-17 17:01 UTC: 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.
- **investigating** 2026-10-17 17:31 UTC: 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.
- **identified** 2026-10-17 17:35 UTC: 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.
- **identified** 2026-10-17 18:06 UTC: 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.
- **identified** 2026-10-17 18:31 UTC: We are actively working to clear the delayed flow emails and restore normal flow email sending. Some customers may still see flow emails send later than expected while this work completes. Immediate sends remain unaffected. We will share another update shortly.
- **identified** 2026-10-17 19:04 UTC: We are still working to clear the delayed flow execution, and flow sending has not yet returned to normal. Some customers may continue to see messages send later than expected while we complete this work. Immediate sends remain unaffected. We will share another update shortly.
- **identified** 2026-10-17 19:42 UTC: We are continuing to work on the fix for this issue. Some customers may continue to experience delays in flow processing while we resolve this. Immediate sends remain unaffected. We will share another update shortly.
- **identified** 2026-10-17 20:22 UTC: We are continuing to work on resolving the delays affecting flow processing. Some customers may continue to experience delays in their flows while we work through this. Immediate sends remain unaffected, and delayed messages remain queued while we work to process them. We will share another update shortly.
- **monitoring** 2026-10-17 20:59 UTC: Flow processing has resumed and the delayed backlog is actively clearing. This incident affected all flow processing - including flow-triggered email, SMS, WhatsApp and push messages, as well as flow updates to profiles and lists. Some customers may continue to see delays until the backlog fully catches up. Immediate sends were not affected. We continue to monitor closely and appreciate your patience throughout this incident.
- **monitoring** 2026-10-17 21:34 UTC: Delays have now largely cleared, though some customers may still see flow messages send later than expected. We continue to monitor closely and appreciate your patience throughout this incident.
- **resolved** 2026-10-17 21:51 UTC: Flow processing has returned to normal, and delayed flow actions - including email, SMS, and push messages, as well as profile and list updates - have fully caught up. Immediate sends were not affected. We apologize for the disruption this caused. This incident has been resolved.

## Rewindex changes for this incident

- 2026-10-17 17:01 UTC: [Major incident: Flow Sending Delays](https://rewindex.com/change/if6243f0673327b.md)
- 2026-10-17 18:33 UTC: [Incident updated: Flow Sending Delays](https://rewindex.com/change/r7e504705c663e8.md)
- 2026-10-17 19:13 UTC: [Incident updated: Flow Sending Delays](https://rewindex.com/change/r20dcdf6ac277c7.md)
- 2026-10-17 19:43 UTC: [Incident updated: Flow Sending Delays](https://rewindex.com/change/r02256c12541fc9.md)
- 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)


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Canonical: https://rewindex.com/company/klaviyo/incidents/h0nhg0mtrj77 · Markdown: https://rewindex.com/company/klaviyo/incidents/h0nhg0mtrj77.md · JSON: https://rewindex.com/api/v1/companies/klaviyo/incidents/h0nhg0mtrj77 · Generated 2026-10-18T09:56:28.073Z