One of our clients has a domain name which their servers are sending us that does not exist but we still need those emails to reach us. Is there a way to allow this domain through but keep all others rejected?

Jun 30 06:32:47 postfix/smtpd[15550]: NOQUEUE: reject: RCPT from 450 4.1.8 <>: Sender address rejected: Domain not found; from=<> to=<> proto=ESMTP helo=<>