2.x.x — Success codes
Class 2 enhanced status codes report a successful delivery outcome. When one appears inside a bounce flow, inspect the event classification before changing recipient state.
A leading 2 means the server accepted the action it describes. Read it together with the complete SMTP response or DSN, because a success line inside an asynchronous report can still accompany a later problem.
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.
- 2.0.0Other undefined success statusCode 2.0.0 is a general success status: only class 2 is known, with no more specific status. It is not a message rejection.CategoryOther and undefinedRecommended actionCheck the full context
- 2.1.5Destination address is validThe specified recipient mailbox address was found to be valid. This is a success confirmation, not a message rejection.CategoryAddressingRecommended actionCheck the full context
- 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.CategoryMail systemRecommended 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.CategoryMail systemRecommended actionCheck the full context
- 2.5.0Other or undefined protocol statusCode 2.5.0 is a general status concerning the protocol needed to pass the message to the next system. It provides no more specific detail, but the leading digit 2 means success, not rejection.CategoryDelivery protocolRecommended actionCheck the full context
- 2.6.4Conversion with data loss performedThe message was delivered, but delivery required a conversion in which some data was lost. This is a successful-result warning, not a rejection.CategoryMessage content and formatRecommended actionCheck the full context
- 2.6.8Required UTF-8 reply not permitted by the SMTP clientA reply needed to show the mailbox name would have to contain a UTF-8 string, but the SMTP client does not permit that form of reply. Code 2.6.8 reports this as a success status, not a rejection.CategoryMessage content and formatRecommended actionCheck the full context
- 2.7.0Other or undefined security status (success)The mail system reported a general security-related status that could not be described by a more specific code. The leading digit 2 denotes success, not message rejection.CategorySecurity, authentication and policyRecommended actionCheck the full context
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