Good day! (beginning to apologize for my English)

Description of the problem:
There is a test server Zimbra that keeps domain "", it has a couple of users to send external relay is. Tell me how to get Zimbra if the user of the domain sends an email to the same domain (, but which is irrelevant, then Zimbra sent this letter to the relay, not cursing at the lack of a domain user.?

as I understand it, this is called smtpd_recipient_restritstions option, but I can not clean it up, or am I wrong?