Answer
A message has been sent to an account that does not exist on this server. The current policy is to reject such email so it has been rejected at the protocol stage. By rejecting the message at the RCPT clause, GMS is saving considerable network bandwidth because the message body has not been sent over the network.
In this case, session Undefined was receiving a message from the server at Undefined apparently from Undefined to Undefined. The message has been rejected with
Undefined
If you want this email message to be delivered, you will need to either
- change the "Unknown User Action" for this domain; or
- ask the server/client sending the email to correct the destination address.
See Also:
- How do I contact the owner of a remote server?
- What is SMTP Response Code Theory?
- How do I contact the owner of a client?
Keywords:unknownuseraction mail bandwidth reject