SparkPost Outage History

SparkPost experienced increased bounce rates and delivery delays for emails sent to Apple-hosted domains due to an Apple iCloud Mail outage, while messages to non-Apple domains remained unaffected. The incident affected SMTP delivery services in both USA and Europe regions for 2 hours. The issue was resolved when Apple fixed their iCloud Mail outage, and SparkPost performed cleanup of suppression lists to remove any recipients that were incorrectly suppressed during the incident.

SparkPost experienced a major incident affecting email delivery in the US region, with users experiencing elevated delays when sending emails through SMTP delivery services. The issue impacted the US region's email delivery infrastructure for approximately 9.7 hours. The system was fully recovered and the incident was resolved after monitoring confirmed stable operations.

SparkPost experienced increased delivery latency affecting outbound email messages for customers in both US and EU regions, impacting SMTP delivery services. The incident caused delayed or slow message delivery for some customers over a 36-minute period. The service recovery was observed and monitored before the incident was fully resolved.

SparkPost experienced elevated temporary rejection rates for emails delivered to Microsoft-hosted addresses (Outlook.com, Hotmail, etc.) due to an industry-wide issue on Microsoft's side that caused IP rate limiting and delivery delays. The incident lasted 23.8 hours and affected mailbox provider services, with Microsoft acknowledging and actively investigating the problem. Microsoft resolved the issue by making additional changes on February 26th to remediate the IP rate limiting and rejection problems.

SparkPost experienced elevated 5xx error rates and latency on their Transmissions API for US-hosted customers due to a core networking issue affecting sending clusters. The incident impacted email injection capabilities for some customers over a 37-minute period. The team identified the root cause, implemented a fix, and resolved the issue after monitoring confirmed restoration of normal service.

SparkPost experienced delayed outbound message delivery affecting US-hosted customers for 3.3 hours. The issue impacted SMTP delivery services in the USA region, though no messages were lost during the incident. The problem was identified, fixed, and resolved after a monitoring period.