SMTP 214 Help Message vs 553 Mailbox Name Invalid
SMTP 214 (Help Message) is a 2xx Positive Completion response, while 553 (Mailbox Name Invalid) 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, 553 means that the requested action was not taken because the mailbox name is syntactically incorrect. The email address does not conform to the expected format.
Description
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.
Quand vous le voyez
After sending the HELP command to the SMTP server. The response lists available commands or provides usage details for the command you specified.
Comment résoudre
No fix needed — this is a normal informational response. Use the provided help text to understand which commands the server supports.
Description
The requested action was not taken because the mailbox name is syntactically incorrect. The email address does not conform to the expected format.
Quand vous le voyez
When the sender or recipient address contains invalid characters, improper formatting, or violates the server's naming conventions.
Comment résoudre
Check the email address format — ensure it follows the standard [email protected] pattern with valid characters. Remove any spaces, special characters, or encoding issues from the address.
Différences clés
214 is a 2xx Positive Completion response, while 553 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 553: The requested action was not taken because the mailbox name is syntactically incorrect. The email address does not conform to the expected format.
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 553 when when the sender or recipient address contains invalid characters, improper formatting, or violates the server's naming conventions.
Quand utiliser lequel
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 553 (Mailbox Name Invalid): Check the email address format — ensure it follows the standard [email protected] pattern with valid characters. Remove any spaces, special characters, or encoding issues from the address.