When attempting to send an email to an address on your server, you receive a bounce-back email containing the following message.
The account or domain may not exist; they may be blacklisted, or missing the proper DNS entries.
This message can occur when the domain's mail routing is set to remote.
The domain's mail routing can be changed from "remote" to "local" from cPanel or WHM. The steps to change the mail routing from either location can be found in the following article.