Backscatter[Dot]org Blacklisted

Discussion in 'Installation/Configuration' started by Chris West, Jun 22, 2019.

  1. Chris West

    Chris West New Member

    Hi,

    got an issue reported by one of my users.
    He can't send emails to @t-online.de users.
    After researching I found out that my mail server ip is listed for at least 4 weeks on the list.
    This is really critical for me.
    To reduce back scatter I already followed several suggestions on the net.
    But I checked on it again and the IP was again reported.

    Heres my postfix main.cf

    Code:
    # See /usr/share/postfix/main.cf.dist for a commented, more complete version
    
    
    # Debian specific:  Specifying a file name will cause the first
    # line of that file to be used as the name.  The Debian default
    # is /etc/mailname.
    #myorigin = /etc/mailname
    
    smtpd_banner = $myhostname ESMTP $mail_name (Debian/GNU)
    biff = no
    
    # appending .domain is the MUA's job.
    append_dot_mydomain = no
    
    # Uncomment the next line to generate "delayed mail" warnings
    #delay_warning_time = 4h
    
    readme_directory = /usr/share/doc/postfix
    
    # See http://www.postfix.org/COMPATIBILITY_README.html -- default to 2 on
    # fresh installs.
    compatibility_level = 2
    
    # TLS parameters
    smtpd_tls_cert_file = /etc/postfix/smtpd.cert
    smtpd_tls_key_file = /etc/postfix/smtpd.key
    smtpd_use_tls = yes
    smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
    smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
    
    # See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
    # information on enabling SSL in the smtp client.
    
    smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination
    myhostname = hostname.server.tld
    alias_maps = hash:/etc/aliases, hash:/var/lib/mailman/data/aliases
    alias_database = hash:/etc/aliases, hash:/var/lib/mailman/data/aliases
    myorigin = /etc/mailname
    mydestination = hostname.server.tld, localhost, localhost.localdomain
    relayhost =
    mynetworks = 127.0.0.0/8 [::1]/128
    mailbox_size_limit = 0
    recipient_delimiter = +
    inet_interfaces = all
    inet_protocols = all
    html_directory = /usr/share/doc/postfix/html
    virtual_alias_domains =
    virtual_alias_maps = hash:/var/lib/mailman/data/virtual-mailman, 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 = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination, reject_rbl_client zen.spamhaus.org, check_recipient_access mysql:/etc/postfix/mysql-virtual_recipient.cf, check_recipient_access mysql:/etc/postfix/mysql-virtual_policy_greylist.cf
    smtpd_tls_security_level = may
    transport_maps = hash:/var/lib/mailman/data/transport-mailman, 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, reject_invalid_helo_hostname, reject_unknown_helo_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
    header_checks = pcre:/etc/postfix/header_checks
    mime_header_checks = regexp:/etc/postfix/mime_header_checks
    nested_header_checks = regexp:/etc/postfix/nested_header_checks
    body_checks = pcre:/etc/postfix/body_checks
    owner_request_special = no
    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
    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
    message_size_limit = 0
    smtputf8_autodetect_classes = all
    #smtputf8_enable = no
    notify_classes = 2bounce, data, delay, resource, software
    
    #postscreen_greet_action = enforce
    I also added header_checks

    Code:
    # Do not indent the patterns between "if" and "endif".
    if /^Received:/
    /^Received: +from +(porcupine\.org) +/
        reject forged client name in Received: header: $1
    /^Received: +from +[^ ]+ +\(([^ ]+ +[he]+lo=|[he]+lo +)(porcupine\.org)\)/
        reject forged client name in Received: header: $2
    /^Received:.* +by +(porcupine\.org)\b/
        reject forged mail server name in Received: header: $1
    endif
    /^Message-ID:.* <!&!/ DUNNO
    /^Message-ID:.*@(porcupine\.org)/
        reject forged domain name in Message-ID: header: $1
    and body_checks
    What else can I do to reduce the backscatter?
    My people are already complaining.
    I know the list from backscatter.org should not be used by this way, but I have to deal with this.

    Hope somebody experienced this already.

    thx
    Chris
     
  2. Taleman

    Taleman Well-Known Member HowtoForge Supporter

  3. Chris West

    Chris West New Member

    Hi,
    I have been listed here:

    www[dot]backscatterer[dot]org

    according to several online tests for Backscatter, my server is not sending this.
    I'm irritated honestly.
    reverse DNS is set up correctly at the provider and name server.
    None of the tests of mxtoolbox are without any results.
     

Share This Page