Announcing the “noreply” string is now reserved for support addresses on Zendesk domains









Announced on
Rollout starts
Rollout ends


June 8, 2026
August 10, 2026
August 21, 2026


Zendesk is standardizing its email security infrastructure by reserving the specific "noreply" text string for support addresses for internal system usage. Therefore, if your account uses a support address with the specific "noreply" string on a Zendesk domain, you must migrate to an alternative address. This update ensures reliable, standardized fallback communication when customer connections are unavailable and helps prevent confusion regarding system emails. This change only applies to support addresses on a Zendesk domain (such as yoursubdomain.zendesk.com). If you use an external "noreply" address via an email connector or standard email forwarding (such as noreply@yoursubdomain.com), your account is not affected. This article includes these sections:
What's changing?
Why is Zendesk making this change?
What do I need to do?
What's changing? Zendesk is reserving the specific "noreply" string for system-generated support addresses on Zendesk domains (for example, noreply@yoursubdomain.zendesk.com). As a result of this update:
You can no longer create new support addresses that use the exact "noreply" string on a Zendesk domain and any +id noreply address such as noreply+id@yoursubdomain.zendesk.com.
If you currently use a support address on a Zendesk domain containing this exact string, you must migrate to a new support address.
Once the rollout is complete, Zendesk will begin rejecting incoming mail sent to these exact "noreply" domain addresses with an SMTP 550 error response.
Why is Zendesk making this change? This update is part of ongoing security improvements to our native support address architecture. Zendesk requires dedicated, reserved fallback addresses to safely transmit messages to end users if a customer's primary email connection goes down. Reserving the "noreply" string standardizes this behavior across all internal Zendesk senders and ensures clear, consistent routing for last-resort system communications. What do I need to do? If your account uses the specific "noreply" string on a Zendesk domain, you must migrate to an alternative address. To maintain uninterrupted email service, update your support address to a variation that does not exactly match the reserved string, such as no_reply@yoursubdomain.zendesk.com. See the Zendesk Help Center for more information on adding and managing support addresses. If you have feedback or questions related to this announcement, visit our community forum where we collect and manage customer product feedback. For general assistance with your Zendesk products, contact Zendesk Customer Support.