I am using the ubuntu 18.04 server.
When I am trying to send an email to a particular user, then this error has occurred:
A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:
SMTP error from remote mail server after RCPT TO:<[email protected]>:
550-Verification failed for <[email protected]>
550-The mail server does not recognize [email protected] as a valid sender.
550 Sender verify failed
What is that error? Is there anything that I can do on my side?
I follow the steps from here and now is working perfectly.