when i send email below address i got this message.(several time)
1)Delivery to the following recipient failed permanently:
Technical details of permanent failure:
Google tried to deliver your message, but it was rejected by the server for the recipient domain bigpond.com by extmail.bigpond.com. [126.96.36.199].
The error that the other server returned was:
550 5.1.1 <firstname.lastname@example.org> recipient rejected. IB603a
2)Delivery Status Notification (Failure)
The following message to <email@example.com> was undeliverable.
The reason for the problem:
5.1.0 - Unknown address error 550-'sorry, no mailbox here by that name (#5.1.1)'
3)Mail delivery failed: returning message to sender
This message was created automatically by mail delivery software.
A message that you sent could not be delivered to one or more of
its recipients. This is a permanent error. The following address
SMTP error from remote server after RCPT command:
5.1.1 <firstname.lastname@example.org> recipient rejected. IB603a
can anyone help me how to solve this.