Mailgun incident
TLS Certificate Validation Errors for Clients Without SNI
Mailgun experienced a major incident on April 15, 2026 affecting API, lasting 1h 54m. The incident has been resolved; the full update timeline is below.
Affected components
API
Update timeline
- investigating Apr 15, 2026, 01:40 PM UTC
We are currently investigating an issue where customers making HTTPS requests to our API without Server Name Indication (SNI) enabled are being presented with an expired SSL/TLS certificate. This results in certificate validation failures for affected clients.
- identified Apr 15, 2026, 01:42 PM UTC
The issue has been identified and a fix is being implemented.
- monitoring Apr 15, 2026, 02:02 PM UTC
A fix has been implemented and we are monitoring the results.
- resolved Apr 15, 2026, 03:34 PM UTC
This incident has been resolved.