SMTP 211 System Status vs 535 Authentication Failed
SMTP 211 (System Status) is a 2xx Positive Completion response, while 535 (Authentication Failed) 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, 535 means that the authentication credentials provided are invalid. The username, password, or authentication mechanism was rejected by the server.
คำอธิบาย
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.
เมื่อคุณพบเห็น
When querying the mail server for its status or capabilities. The server is sharing diagnostic or informational details about itself.
วิธีแก้ไข
No fix needed — this is an informational response. If the status indicates a problem, review the server's configuration or contact the mail administrator.
คำอธิบาย
The authentication credentials provided are invalid. The username, password, or authentication mechanism was rejected by the server.
เมื่อคุณพบเห็น
After submitting incorrect credentials via the AUTH command. The username or password does not match any account on the server.
วิธีแก้ไข
Double-check your username and password. If using an app password (e.g., Gmail, Outlook), ensure it is current and has not been revoked. Also verify the correct SASL mechanism (PLAIN, LOGIN, etc.).
ความแตกต่างหลัก
211 is a 2xx Positive Completion response, while 535 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 535: The authentication credentials provided are invalid. The username, password, or authentication mechanism was rejected by the 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 535 when after submitting incorrect credentials via the AUTH command. The username or password does not match any account on the server.
ควรใช้อันไหนเมื่อไร
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 535 (Authentication Failed): Double-check your username and password. If using an app password (e.g., Gmail, Outlook), ensure it is current and has not been revoked. Also verify the correct SASL mechanism (PLAIN, LOGIN, etc.).