SMTP 211 System Status vs 502 Command Not Implemented
SMTP 211 (System Status) is a 2xx Positive Completion response, while 502 (Command Not Implemented) is a 5xx Permanent Negative response. 211 indicates that a system status reply providing information about the mail server's current state. This is typically sent in response to a HELP or system inquiry 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.
الوصف
A system status reply providing information about the mail server's current state. This is typically sent in response to a HELP or system inquiry command.
متى تراه
When querying the mail server for its status or capabilities. The server is sharing diagnostic or informational details about itself.
كيفية الإصلاح
No fix needed — this is an informational response. If the status indicates a problem, review the server's configuration or contact the mail administrator.
الوصف
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.
متى تراه
When using optional SMTP commands like VRFY, EXPN, or TURN that the server administrator has disabled, often for security or anti-spam reasons.
كيفية الإصلاح
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.
الفروق الرئيسية
211 is a 2xx Positive Completion response, while 502 is a 5xx Permanent Negative response.
SMTP 211: A system status reply providing information about the mail server's current state. This is typically sent in response to a HELP or system inquiry 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 211 when when querying the mail server for its status or capabilities. The server is sharing diagnostic or informational details about itself.
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.
متى تستخدم أيًا منهما
For 211 (System Status): No fix needed — this is an informational response. If the status indicates a problem, review the server's configuration or contact the mail administrator. 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.