Elevated inbound recipient rejected

This incident has been resolved.

On November 13th, Mailgun incorrectly rejected a subset of inbound emails with a 550 "recipient rejected" error. Senders received bounce notifications even though delivery should have succeeded. Affected timeframes: US region: 05:14 to 06:41 UTC and 14:55 to 15:48 UTC EU region: 14:55 to 15:48 UTC Based on our analysis, approximately 25% of US inbound traffic and 50% of EU inbound traffic had a chance to have been impacted during these windows. We're unable to provide exact counts due to gaps in our logging for rejected inbound mail, which we have since corrected.