mail relay

I have been receiving this error when testing. Sep 12 11:16:43 pmg postfix/error[955]: 147123C14C4: to=<kransom@l.domain.org>, orig_to=<kransom@g.domain.org>, relay=none, delay=0.11, delays=0.07/0.01/0/0.03, dsn=5.1.1, status=bounced (User unknown in virtual alias table) It was suggested in...