Error 553 Undelivered Mail Returned to Sender

Error 553 Undelivered Mail Returned to Sender

I have been receiving the above error when I try to email my client. I'm concerned that your IP is being blacklisted. I'm attaching a .jpg of the error I have received.  Is it possible for you to get it de-listed? I don't think I can do anything on my end.

Thank you

James Wright