SMTP 214 Help Message vs 451 Local Error
SMTP 214 (Help Message) is a 2xx Positive Completion response, while 451 (Local Error) is a 4xx Transient Negative response. 214 indicates that a help message response containing information about the server's supported commands or a specific command's usage. This is a human-readable reply to the HELP command. In contrast, 451 means that the requested action was aborted due to a local error in processing. The server encountered an internal issue that prevented it from completing the command.
描述
A help message response containing information about the server's supported commands or a specific command's usage. This is a human-readable reply to the HELP command.
何时出现
After sending the HELP command to the SMTP server. The response lists available commands or provides usage details for the command you specified.
如何修复
No fix needed — this is a normal informational response. Use the provided help text to understand which commands the server supports.
描述
The requested action was aborted due to a local error in processing. The server encountered an internal issue that prevented it from completing the command.
何时出现
When the receiving server hits an internal error such as a database failure, DNS lookup timeout, or anti-spam filter processing error.
如何修复
Retry the message later. If you control the server, check its logs for the specific error — common causes include DNS resolution failures, disk I/O errors, or database connectivity issues.
主要区别
214 is a 2xx Positive Completion response, while 451 is a 4xx Transient Negative response.
SMTP 214: A help message response containing information about the server's supported commands or a specific command's usage. This is a human-readable reply to the HELP command.
SMTP 451: The requested action was aborted due to a local error in processing. The server encountered an internal issue that prevented it from completing the command.
You encounter 214 when after sending the HELP command to the SMTP server. The response lists available commands or provides usage details for the command you specified.
You encounter 451 when when the receiving server hits an internal error such as a database failure, DNS lookup timeout, or anti-spam filter processing error.
何时使用哪个
For 214 (Help Message): No fix needed — this is a normal informational response. Use the provided help text to understand which commands the server supports. For 451 (Local Error): Retry the message later. If you control the server, check its logs for the specific error — common causes include DNS resolution failures, disk I/O errors, or database connectivity issues.