2.2.1.5 SMTP_AUTH_Other_Failure_Response Message

The SMTP_AUTH_Other_Failure_Response message is defined as follows. This is actually a class of messages whose syntax and interpretation are defined in [RFC2821] section 4.2 and [RFC2554] sections 4 and 6. They indicate an abnormal termination of the NTLM authentication negotiation, which can occur for various reasons such as software errors, lack of system resources, and so on. For the purposes of this document, SMTP_AUTH_Other_Failure_Response is defined as any SMTP message other than SMTP_AUTH_NTLM_Succeeded_Response, SMTP_AUTH_Fail_Response, and SMTP_AUTH_NTLM_BLOB_Response. The interpretation of SMTP_AUTH_Other_Failure_Response, and the suggested client action when receiving such a message, is defined in [RFC2821] section 4.3. This message represents an exit from AUTH and, as such, is not really a part of AUTH negotiation.