SMTP 211 System Status vs 500 Syntax Error
SMTP 211 (System Status) is a 2xx Positive Completion response, while 500 (Syntax Error) 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, 500 means that the server could not recognize the command due to a syntax error. The command line was malformed or the command is not recognized by this server.
Mô tả
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.
Khi bạn thấy mã này
When querying the mail server for its status or capabilities. The server is sharing diagnostic or informational details about itself.
Cách khắc phục
No fix needed — this is an informational response. If the status indicates a problem, review the server's configuration or contact the mail administrator.
Mô tả
The server could not recognize the command due to a syntax error. The command line was malformed or the command is not recognized by this server.
Khi bạn thấy mã này
When you send a command the server does not understand — often due to a typo, unsupported command, or an excessively long line.
Cách khắc phục
Check the command spelling and syntax against the SMTP specification. Ensure the command line does not exceed 512 characters and uses proper CRLF line endings.
Sự khác biệt chính
211 is a 2xx Positive Completion response, while 500 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 500: The server could not recognize the command due to a syntax error. The command line was malformed or the command is not recognized by this server.
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 500 when when you send a command the server does not understand — often due to a typo, unsupported command, or an excessively long line.
Khi nào dùng cái nào
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 500 (Syntax Error): Check the command spelling and syntax against the SMTP specification. Ensure the command line does not exceed 512 characters and uses proper CRLF line endings.