SMTP 250 OK vs 530 Authentication Required
SMTP 250 (OK) is a 2xx Positive Completion response, while 530 (Authentication Required) is a 5xx Permanent Negative response. 250 indicates that the requested mail action has been completed successfully. This is the most common positive response in SMTP, returned after HELO/EHLO, MAIL FROM, RCPT TO, and DATA completion. In contrast, 530 means that the server requires authentication before accepting mail commands. You must issue the AUTH command with valid credentials before attempting to send mail.
Description
The requested mail action has been completed successfully. This is the most common positive response in SMTP, returned after HELO/EHLO, MAIL FROM, RCPT TO, and DATA completion.
Quand vous le voyez
After nearly every successful SMTP command — greeting, specifying sender, adding recipients, or completing message delivery. This is the standard success confirmation.
Comment résoudre
No fix needed — the command was accepted. If a command that should succeed returns a different code, check the command syntax and server policies.
Description
The server requires authentication before accepting mail commands. You must issue the AUTH command with valid credentials before attempting to send mail.
Quand vous le voyez
When trying to send mail through a server that requires authentication (typical for submission on port 587) without first logging in with the AUTH command.
Comment résoudre
Authenticate using the AUTH command with your username and password before sending MAIL FROM. Ensure your email client is configured with the correct SMTP credentials and authentication method.
Différences clés
250 is a 2xx Positive Completion response, while 530 is a 5xx Permanent Negative response.
SMTP 250: The requested mail action has been completed successfully. This is the most common positive response in SMTP, returned after HELO/EHLO, MAIL FROM, RCPT TO, and DATA completion.
SMTP 530: The server requires authentication before accepting mail commands. You must issue the AUTH command with valid credentials before attempting to send mail.
You encounter 250 when after nearly every successful SMTP command — greeting, specifying sender, adding recipients, or completing message delivery. This is the standard success confirmation.
You encounter 530 when when trying to send mail through a server that requires authentication (typical for submission on port 587) without first logging in with the AUTH command.
Quand utiliser lequel
For 250 (OK): No fix needed — the command was accepted. If a command that should succeed returns a different code, check the command syntax and server policies. For 530 (Authentication Required): Authenticate using the AUTH command with your username and password before sending MAIL FROM. Ensure your email client is configured with the correct SMTP credentials and authentication method.