SMTP 214 Help Message vs 502 Command Not Implemented
SMTP 214 (Help Message) is a 2xx Positive Completion response, while 502 (Command Not Implemented) is a 5xx Permanent 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, 502 means that the command is recognized by the SMTP specification but is not implemented on this server. The server understands the command but has chosen not to support it.
설명
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.
이 코드를 보게 되는 경우
After sending the HELP command to the SMTP server. The response lists available commands or provides usage details for the command you specified.
해결 방법
No fix needed — this is a normal informational response. Use the provided help text to understand which commands the server supports.
설명
The command is recognized by the SMTP specification but is not implemented on this server. The server understands the command but has chosen not to support it.
이 코드를 보게 되는 경우
When using optional SMTP commands like VRFY, EXPN, or TURN that the server administrator has disabled, often for security or anti-spam reasons.
해결 방법
Use an alternative approach — for example, if VRFY is disabled, send a test email instead of verifying the address. Check the server's EHLO response for supported extensions.
주요 차이점
214 is a 2xx Positive Completion response, while 502 is a 5xx Permanent 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 502: The command is recognized by the SMTP specification but is not implemented on this server. The server understands the command but has chosen not to support it.
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 502 when when using optional SMTP commands like VRFY, EXPN, or TURN that the server administrator has disabled, often for security or anti-spam reasons.
언제 어떤 것을 사용할지
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 502 (Command Not Implemented): Use an alternative approach — for example, if VRFY is disabled, send a test email instead of verifying the address. Check the server's EHLO response for supported extensions.