# SparkPost: Elevated percentage of API calls failing

- Impact (vendor’s label): minor
- Status: resolved
- Started: 2025-05-13 05:22 UTC · Resolved: 2025-05-13 11:29 UTC · Duration: 6.1 h
- Updates: 4 · Affected components: Metrics API - Metrics API - USA, Metrics API - USA, Blocklist API - Blocklist API - USA, Blocklist API - USA, Transmissions API - Transmissions API - USA, Transmissions API - USA, Transmissions API - EUROPE, Transmissions API - Transmissions API - EUROPE, Events API - EUROPE, Events API - Events API - EUROPE, SMTP API - EUROPE, SMTP API - SMTP API - EUROPE, SMTP API - SMTP API - USA, SMTP API - USA, Events API - Events API - USA, Events API - USA, Sending Domains API - Sending Domains API - USA, Sending Domains API - USA, Alerts API - Alerts API - USA, Alerts API - USA, Suppression List API - EUROPE, Suppression List API - Suppression List API - EUROPE, Metrics API - EUROPE, Metrics API - Metrics API - EUROPE, Suppression List API - Suppression List API - USA, Suppression List API - USA, Alerts API - Alerts API - EUROPE, Alerts API - EUROPE, Blocklist API - Blocklist API - EUROPE, Blocklist API - EUROPE, Sending Domains API - EUROPE, Sending Domains API - Sending Domains API - EUROPE
- [Vendor status page: https://stspg.io/4n920rwx827s](https://stspg.io/4n920rwx827s)
- [Company: SparkPost](https://rewindex.com/company/sparkpost.md)

## Timeline of updates

- **investigating** 2025-05-13 05:22 UTC: We are investigating an unexpected but small increase in the percentage of API calls failing since 01:30UTC. Approximately 0.015% of  API calls are failing with a HTTP 504 (Gateway timeout) error.   We will update this incident as we have more information.
- **investigating** 2025-05-13 05:52 UTC: We are still investigating.  During the period, the error rate has remained low as initially reported, approximately ~0.015%.
- **identified** 2025-05-13 06:26 UTC: We have identified the cause as a set of stale IPs for an upstream service. We are now validating the approach for remediation.
- **resolved** 2025-05-13 11:29 UTC: After a period of extended monitoring, we have confirmed the remediation has completely resolved the issue.  Requests and error rates have been normal since 06:27UTC


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Canonical: https://rewindex.com/company/sparkpost/incidents/pnn15xghwjlm · Markdown: https://rewindex.com/company/sparkpost/incidents/pnn15xghwjlm.md · JSON: https://rewindex.com/api/v1/companies/sparkpost/incidents/pnn15xghwjlm · Generated 2026-10-19T21:09:11.762Z