Iterable change history: Email send delays for some US-hosted SparkPost traffic

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.