Something
public text v1 · immutablemain.cf:
smtpd_client_restrictions =
permit_mynetworks,
reject_unknown_client,
reject_rbl_client sbl.spamhaus.org,
reject_rbl_client bl.spamcop.net,
reject_rbl_client relays.ordb.org,
check_client_access hash:/etc/postfix/access
/etc/postfix/access:
.ru REJECT no spam