Mail system
The destination mail system's availability, capability, configuration, or operating state.
This category covers eight reviewed codes concerning the state of the destination mail system. They include success statuses for a general system outcome and a changed requested priority, temporary failures involving an unspecified system condition, exhausted storage, or a system not accepting messages, and permanent outcomes for a general system problem, a system not accepting messages, and a per-message size limit being exceeded. The complete code class matters: a similar system detail can appear with a leading 2, 4, or 5, so the category alone does not establish whether the report records success, a temporary condition, or a permanent failure.
Codes in this category
This inventory contains only reviewed codes assigned to this subject. Open a code to see its evidence, diagnostic steps and owner-specific actions.
- 2.3.0Other or undefined mail system statusThe destination system exists and normally accepts mail, but its condition caused a general DSN to be generated. Because the code begins with 2, it describes success, not a message rejection.Delivery status2xx · SuccessRecommended actionCheck the full context
- 2.3.6Requested priority was changedThe message was accepted for relay or delivery, but the requested priority—including a possible implied default—was not retained. The system reported a new priority instead. This is a success status, not a rejection.Delivery status2xx · SuccessRecommended actionCheck the full context
- 4.3.0Other or undefined temporary mail-system statusThe destination system exists and normally accepts mail, but a general problem in that system prevented delivery during this attempt. The leading digit 4 denotes a temporary failure, so delivery may be retried in a controlled way.Delivery status4xx · Temporary failureRecommended actionControlled retry
- 4.3.1Temporarily full mail systemThe mail system exceeded its available storage during this attempt. This is a system-wide resource problem, so an individual recipient may be unable to free space on their own. Because the code begins with 4, delivery may be retried in a controlled way.Delivery status4xx · Temporary failureRecommended actionControlled retry
- 4.3.2System temporarily not accepting network messagesThe host on which the recipient's mailbox resides is not currently accepting messages. Because the code begins with 4, this is a temporary failure and delivery may be retried in a controlled way.Delivery status4xx · Temporary failureRecommended actionControlled retry
- 5.3.0Other or undefined permanent mail-system statusThe destination system exists and normally accepts mail, but a general problem in that system caused a permanent failure. Do not retry the same unchanged attempt.Delivery status5xx · Permanent failureRecommended actionDo not retry unchanged
- 5.3.2System not accepting network messages — permanent failureThe host on which the recipient's mailbox resides is not accepting messages and rejected the current request as a permanent failure. Do not retry the unchanged send.Delivery status5xx · Permanent failureRecommended actionDo not retry unchanged
- 5.3.4Message exceeds the system size limitThe message was permanently rejected because it is larger than the system's per-message size limit. Do not retry the same unchanged send.Delivery status5xx · Permanent failureRecommended actionDo not retry unchanged
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