...
Ýou mean *client*.
smtp_client_restrictions = reject_unknown_client_hostname
NOTE that this is a very heavy restriction and will cause many, many
false positives.
I'll use warn-if-reject to see how is going.
Instead, use the milder (but equally effective)
smtp_client_restrictions = reject_unknown_reverse_client_hostname
This will reject all clients that do not have a PTR entry for their IP.
See http://www.postfix.org/postconf.5.html#smtpd_client_restrictions for
the full list.
I implemented your recommended milder setup.
Thanks.
Bruno
