Postmark experienced a major incident on August 18, 2026, lasting 1d 7h. The incident has been resolved; the full update timeline is below.
Update timeline
- investigating Aug 19, 2026, 12:48 PM UTC
We are investigating an issue with open webhook delivery delays.
- investigating Aug 19, 2026, 06:43 PM UTC
Previously backlogged open webhook events are processing. We will update as we progress.
- resolved Aug 19, 2026, 10:12 PM UTC
The issue is now fully resolved. We are continuing to improve our systems, observability, and monitoring to prevent future occurrences. Thank you for your patience. Starting August 18th at ~9:34am CT (~14:34 UTC), Postmark experienced delays in delivering open webhook events. New open events resumed delivery on August 19th at ~8:47am CT (~13:47 UTC), and all backlogged events completed re-delivery at ~4:52pm CT (~21:52 UTC).