TL;DR
General mail-system status in success class 2: not a delivery failure. Operationally informational; if your tools label it a bounce, fix event mapping. Accepted result: do not retry. Deliverability and reputation are usually unaffected.
What this code means
Under success class 2, the X.3.0 mail-system registry pattern means the destination mail system exists and ordinarily accepts mail, yet the reporting path returned only this general status instead of a more specific 2.3.x detail. Subject family 3 addresses mail-system conditions, and the leading digit 2 keeps the report in the success register even when a DSN accompanies the event. Something on the destination system prompted status reporting without identifying a particular queue, capacity, or configuration cause. The status does not establish an outage, a rejection, or delivery completion beyond the acceptance implied by class 2.
Technical meaning
The X.3.0 pattern means another or undefined mail-system status: the destination system exists and ordinarily accepts mail, yet something about that system caused the DSN to be generated. In the 2.3.0 variant, the result class is success.
Delivery status
The leading digit 2 denotes success. Code 2.3.0 does not indicate a temporary or permanent error and is not itself a bounce or rejection signal, even when it appears in a DSN.
- Class
- Success
- Retry
- Do not retry unchanged
- Suppression
- Check the full context
Retry decision
Do not retry based on code 2.3.0 alone because it is a success status. Retrying could create a duplicate; if the expected outcome is not visible, inspect the full event context first.
Suppression decision
Do not add the recipient to a suppression list based solely on code 2.3.0. Before changing the recipient's state, inspect the report context and independent events that confirm any rejection.
Common causes
- The reporting system used the general X.3.0 status in a success DSN without a more specific mail system status.
- The processing layer retained the general 2.3.0 code but did not expose more detailed report context.
Diagnostic steps
- Inspect the raw SMTP response or DSN and confirm that the enhanced code is exactly 2.3.0.
- If the code accompanies an SMTP reply, confirm that the basic reply is in the 2xx class and agrees with the enhanced 2.x.x class.
- Correlate the report with the intended message and send attempt, then review the surrounding context and later events to establish the final outcome.
- If the system displays 2.3.0 as a bounce or rejection, trace the parser, normalization rules, and event mapping.
Actions by owner
Sender administrator
- Classify 2.3.0 as success; do not trigger a retry or automatic suppression solely because of this code.
- Retain the raw report and correct event mapping if the code was routed into rejection handling.
Recipient administrator
- If independent signs of a problem exist, inspect destination-system logs for the correlated transaction; do not infer a rejection or outage from code 2.3.0 alone.
- When the receiving system generated the report, retain the code with enough context to distinguish success from an error.
Provider
- Preserve the raw response or DSN and its success class when normalizing the event.
- Do not present 2.3.0 as a rejection; if a more specific mail system status is available, retain it alongside the general code.
Sources
These sources define what this enhanced status code means, mainly through the IANA registry and related RFCs. When provider examples appear on the page, they come from that provider's published documentation. Follow the links to read the original wording in context.
- SMTP Enhanced Status Codes — IANA registry of enhanced mail system status codes.
- RFC 5248 — A Registry for SMTP Enhanced Mail System Status Codes — Creates and governs the IANA enhanced status code registry.
- RFC 2034 — SMTP Service Extension for Returning Enhanced Error Codes — Defines how SMTP returns enhanced status codes to clients.
- RFC 3463 — Enhanced Mail System Status Codes — Defines the class/subject/detail model for enhanced status codes.
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