Mail server does not recognize my mail as a valid sender

Question

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:<wishtosend@domain.com>:
550-Verification failed for <mymail@example.com>
550-The mail server does not recognize mymail@example.com as a valid sender.
550 Sender verify failed

What is that error? Is there anything that I can do on my side?

Answer 1

I follow the steps from here and now is working perfectly.