DuoCircle experienced a major incident on February 13, 2026, lasting 2d 16h. The incident has been resolved; the full update timeline is below.
Update timeline
- investigating Feb 13, 2026, 12:31 AM UTC
Mailflow Monitoring has been paused while we debug an issue with the round trip calculations. Errors are intermittent but we are pausing so we don't send false positives.
- resolved Feb 15, 2026, 05:00 PM UTC
Resolved: Monitoring Service Interruption — February 13-15, 2026 On February 13, 2026, we identified an issue causing some monitors to incorrectly report email delivery failures. The root cause was a race condition in how our system processed delayed email acknowledgments — in certain timing scenarios, a stale status update could overwrite a more recent one, leading to inaccurate alerts. We implemented a fix that prevents older results from overwriting current status, deployed the update, and placed the system in maintenance mode while we verified stability over a 48-hour observation period. During this window, monitoring continued but outbound notifications were paused to prevent false alerts. As of February 15, all systems have been fully restored and are operating normally. We also took this opportunity to improve our deployment procedures, add boot-order safeguards, and update our operational documentation. We apologize for any inconvenience and appreciate your patience.