im testing email authentication with https://www.unlocktheinbox.com/resources/emailauthentication/ but receiving this errors in logs file…
May 4 09:51:31 email postgrey[1147]: action=greylist, reason=new, client_name=unlocktheinbox.com, client_address=168.144.32.45, sender=mailtest@unlocktheinbox.com, recipient=admin@mydomain.com
May 4 09:51:31 email postfix/smtpd[20925]: NOQUEUE: reject: RCPT from unlocktheinbox.com[168.144.32.45]: 450 4.2.0 <admin@mydomain.com>: Recipient address rejected: Greylisted, see http://postgrey.schweikert.ch/help/mydomain.com.html; from=<mailtest@unlocktheinbox.com> to=<admin@mydomain.com> proto=ESMTP helo=<unlocktheinbox.com>