SMTP 211 System Status vs 251 User Not Local
Both SMTP 211 (System Status) and 251 (User Not Local) belong to the 2xx Positive Completion category. 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. Meanwhile, 251 means that the recipient is not local to the server, but it will forward the message to the specified forwarding address. The server acts as a relay for this recipient.
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 recipient is not local to the server, but it will forward the message to the specified forwarding address. The server acts as a relay for this recipient.
متى تراه
When sending to a recipient whose mailbox is hosted on a different server. The current server knows the forwarding address and will relay the message on your behalf.
كيفية الإصلاح
No fix needed — the message will be forwarded automatically. To avoid relaying, send directly to the address provided in the server's response.
الفروق الرئيسية
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 251: The recipient is not local to the server, but it will forward the message to the specified forwarding address. The server acts as a relay for this recipient.
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 251 when when sending to a recipient whose mailbox is hosted on a different server. The current server knows the forwarding address and will relay the message on your behalf.
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 251 (User Not Local): No fix needed — the message will be forwarded automatically. To avoid relaying, send directly to the address provided in the server's response.