Incident Summary: From September 10 to September 16, 2024, Yahoo implemented email throttling that affected emails sent from our Applicant Tracking System (ATS) to Yahoo users. This caused significant delays in email delivery, and some emails were unable to be delivered after 72 hours.
Customer Impact: During this time, applicants with Yahoo-related email addresses (including Ymail, Verizon, AOL, and other Yahoo-hosted domains) were not receiving emails from the ATS. As a result, some applicants could not be contacted, which may have delayed communication or updates in the hiring process. Users were advised to use other means of communication with these candidates during this timeframe.
Root Cause: The throttling was related to Yahoo’s email filtering policies. Due to Yahoo’s restrictions on sharing IP reputation data, we were unable to determine the exact cause of the throttling.
Resolution Steps: Our team immediately notified affected users and opened a support ticket with Yahoo. We also adjusted our email-sending practices by deploying a one-click unsubscribe feature to better align with Yahoo’s email best practices. Yahoo resolved the throttling on September 16, restoring normal email delivery.
Moving forward, we are implementing long-term improvements to enhance email deliverability and reduce the chances of similar incidents, including refining our email-sending processes and better managing throughput.
If you have any further questions or concerns, please reach out to our support team.