Hello, How configure Postfix to block spam messages using external blacklists, like SPAMHAUS and BARRACUDA? Here my main.cf: Code: virtual_alias_domains = virtual_alias_maps = proxy:mysql:/etc/postfix/mysql-virtual_forwardings.cf, proxy:mysql:/etc/postfix/mysql-virtual_email2email.cf virtual_mailbox_domains = proxy:mysql:/etc/postfix/mysql-virtual_domains.cf virtual_mailbox_maps = proxy:mysql:/etc/postfix/mysql-virtual_mailboxes.cf virtual_mailbox_base = /var/vmail virtual_uid_maps = mysql:/etc/postfix/mysql-virtual_uids.cf virtual_gid_maps = mysql:/etc/postfix/mysql-virtual_gids.cf sender_bcc_maps = proxy:mysql:/etc/postfix/mysql-virtual_outgoing_bcc.cf smtpd_sasl_auth_enable = yes broken_sasl_auth_clients = yes smtpd_sasl_authenticated_header = yes smtpd_restriction_classes = greylisting greylisting = check_policy_service inet:127.0.0.1:10023 smtpd_recipient_restrictions = check_policy_service inet:127.0.0.1:10031, permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination, check_recipient_access mysql:/etc/postfix/mysql-virtual_recipient.cf, reject_rbl_client zen.spamhaus.org, check_recipient_access mysql:/etc/postfix/mysql-virtual_policy_greylist.cf smtpd_end_of_data_restrictions = check_policy_service inet:127.0.0.1:10031 smtpd_use_tls = yes smtpd_tls_security_level = may smtpd_tls_cert_file = /etc/postfix/ssl/server.example.com.crt smtpd_tls_key_file = /etc/postfix/ssl/server.example.com.key smtpd_tls_CAfile = /etc/postfix/ssl/server.example.com.ca-bundle transport_maps = proxy:mysql:/etc/postfix/mysql-virtual_transports.cf relay_domains = mysql:/etc/postfix/mysql-virtual_relaydomains.cf relay_recipient_maps = mysql:/etc/postfix/mysql-virtual_relayrecipientmaps.cf smtpd_sender_login_maps = proxy:mysql:/etc/postfix/mysql-virtual_sender_login_maps.cf proxy_read_maps = $local_recipient_maps $mydestination $virtual_alias_maps $virtual_alias_domains $sender_bcc_maps $virtual_mailbox_maps $virtual_mailbox_domains $relay_recipient_maps $relay_domains $canonical_maps $sender_canonical_maps $recipient_canonical_maps $relocated_maps $transport_maps $mynetworks $smtpd_sender_login_maps smtpd_helo_required = yes smtpd_helo_restrictions = permit_sasl_authenticated, permit_mynetworks, check_helo_access regexp:/etc/postfix/helo_access, reject_invalid_hostname, reject_non_fqdn_hostname, check_helo_access regexp:/etc/postfix/blacklist_helo smtpd_sender_restrictions = check_sender_access regexp:/etc/postfix/tag_as_originating.re, permit_mynetworks, permit_sasl_authenticated, check_sender_access mysql:/etc/postfix/mysql-virtual_sender.cf, check_sender_access regexp:/etc/postfix/tag_as_foreign.re smtpd_client_restrictions = check_client_access mysql:/etc/postfix/mysql-virtual_client.cf smtpd_client_message_rate_limit = 100 maildrop_destination_concurrency_limit = 1 maildrop_destination_recipient_limit = 1 virtual_transport = dovecot mime_header_checks = regexp:/etc/postfix/mime_header_checks nested_header_checks = regexp:/etc/postfix/nested_header_checks body_checks = regexp:/etc/postfix/body_checks smtp_tls_security_level = may smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3 smtpd_tls_protocols = !SSLv2,!SSLv3 smtp_tls_protocols = !SSLv2,!SSLv3 smtpd_tls_exclude_ciphers = RC4, aNULL smtp_tls_exclude_ciphers = RC4, aNULL myhostname = server.example.com mynetworks = 127.0.0.0/8 [::1]/128 dovecot_destination_recipient_limit = 1 smtpd_sasl_type = dovecot smtpd_sasl_path = private/auth content_filter = amavis:[127.0.0.1]:10024 receive_override_options = no_address_mappings bounce_template_file = /etc/postfix/bounce.cf mailbox_size_limit = 0 message_size_limit = 0
There is support for blocking based on an rbl match in ispconfig under Server Config in the Mail tab, 'Real-time Blackhole List'. A much better way to set it up is weighting rbl's using postscreen as at https://git.ispconfig.org/ispconfig/ispconfig3/issues/4239
The problem was Google Public DNS, what doesn't work with SPAMHAUS. Configured OpenDNS to resolve domains and now it works fine.
For a mail server you almost always want/need to run a local caching nameserver; in particular if you use amavis/spamassassin for spam filtering, you need to do this (see https://wiki.apache.org/spamassassin/CachingNameserver)
