On 22 May 2016, at 22:31, Alberto Lepe wrote:
In my understanding, "reject_non_fqdn_sender" should have blocked this
email as the sender's hostname is "unknown".
No. In Postfix nomenclature the "sender" is the SMTP envelope sender
address. The host offering the message is the "client".
If that is right, then why it
is not working? If I'm mistaken, then what do I need to block mails
coming
from "unknown" sources?
There are nuances her, but reject_unknown_reverse_client_hostname is the
safest choice. The other choice is reject_unknown_client_hostname but
that's MUCH riskier because it is a stricter constraint. See the man
page for postconf(5) for the details.
