Outbound DLP Email Delivery Failures via Zscaler SMTP IPs

Zscaler is currently investigating an issue where certain outbound email notifications are failing due to Zscaler SMTP IP addresses being flagged by an external third-party reputation service. This is resulting in email delivery disruptions for some customers. We will continue to provide updates here as the investigation progresses. For detailed updates, please check the Service Status section in your Zscaler customer support portal (CSP). Status changes and additional details will be posted there as they become available.Latest Update - Mon, 09 Feb 2026 04:18:41 UTCZscaler has identified a mitigation strategy to reduce impact from this issue and is actively implementing it to restore full service stability as quickly as possible.Update - Sun, 08 Feb 2026 21:52:11 UTCZscaler is prioritizing the issue and is actively working to isolate the problem and identify the root cause. We appreciate your patience and understanding during this investigation. Additional updates will be provided as more information becomes available.Update - Sun, 08 Feb 2026 23:04:13 UTCWe are continuing to investigate an issue impacting outbound email delivery for some customers. Our teams are actively working to determine the cause and restore normal service. Further updates will be provided as more information becomes available.Update - Mon, 09 Feb 2026 00:22:21 UTCWe are continuing to investigate an issue impacting outbound email delivery. A potential fix has shown positive results in internal testing; however, validation is still ongoing and will require additional time. Zscaler teams remain fully engaged. Further updates will be provided as progress is made.Update - Mon, 09 Feb 2026 02:25:30 UTCZscaler has engaged the email service provider’s support team, and the teams have confirmed that automated anti-spam controls are enforcing a third-party blocklist, which is causing some emails from affected Zscaler SMTP egress IPs to be rejected. Zscaler is working in parallel with the provider and the blocklist operator to expedite delisting of the impacted IPs; escalations are in progress and all impacted IPs have been submitted for review while remediation efforts continue to restore full service stability.Update - Mon, 09 Feb 2026 04:18:41 UTCZscaler has identified a mitigation strategy to reduce impact from this issue and is actively implementing it to restore full service stability as quickly as possible.