Problem to deliver emails to real accounts

Hi,
I've upgrade the server to CentOS 7 from CentOS 6, installed new DirectAdmin and restored backuped files.

Now when I send an email to an alias it works but if I send it to the real account it gives me the following error:
Failed to find user "" from expanded string "${lookup{$domain}lsearch{/etc/virtual/domainowners}{$value}}" for the domain_filter router

Can someone help me?
Thank you.