Well one of my servers got hit hard today in a couple of hours we have gotten over 30K emails to unknown recipients. My problem is postfix is accepting all of these emails into the mail queue then it generates bounces and of course those now sit in the queue. I have tweaked postfix with every known possible scenario on preventing backscatter and i know postfix by default is supposed to auto reject unkown recipients without accepting them into the mail queue, so why is my mail server acting like this? here is my 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 $mail_name (Debian/GNU) biff = no # appending .domain is the MUA's job. append_dot_mydomain = no # Uncomment the next line to generate "delayed mail" warnings #delay_warning_time = 4h readme_directory = /usr/share/doc/postfix # TLS parameters smtpd_tls_cert_file = /etc/postfix/smtpd.cert smtpd_tls_key_file = /etc/postfix/smtpd.key smtpd_use_tls = yes smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache # See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for # information on enabling SSL in the smtp client. myhostname = xxx.xxx.net alias_maps = hash:/etc/aliases alias_database = hash:/etc/aliases myorigin = /etc/mailname mydestination = xxx.xxx.net, localhost, localhost.localdomain relayhost = mynetworks = 127.0.0.0/8 [::1]/128 mailbox_command = procmail -a "$EXTENSION" mailbox_size_limit = 0 recipient_delimiter = + inet_interfaces = all html_directory = /usr/share/doc/postfix/html virtual_alias_domains = virtual_alias_maps = proxy:mysql:/etc/postfix/mysql-virtual_forwardings.cf, 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 = static:5000 virtual_gid_maps = static:5000 smtpd_sasl_auth_enable = yes broken_sasl_auth_clients = yes smtpd_sasl_authenticated_header = yes smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, check_recipient_access mysql:/etc/postfix/mysql-virtual_recipient.cf, reject_unauth_destination, reject_invalid_hostname, reject_unauth_pipelining, reject_non_fqdn_sender, reject_non_fqdn_recipient,reject_unknown_sender_domain, reject_unknown_recipient_domain, reject_rbl_client blackholes.easynet.nl, reject_rbl_client cbl.abuseat.org, reject_rbl_client proxies.blackholes.wirehub.net, reject_rbl_client bl.spamcop.net, reject_rbl_client sbl.spamhaus.org, reject_rbl_client opm.blitzed.org, reject_rbl_client dnsbl.njabl.org, reject_rbl_client multihop.dsbl.org, permit smtpd_tls_security_level = may 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 virtual_create_maildirsize = yes virtual_maildir_extended = yes virtual_mailbox_limit_maps = proxy:mysql:/etc/postfix/mysql-virtual_mailbox_limit_maps.cf virtual_mailbox_limit_override = yes virtual_maildir_limit_message = "The user you are trying to reach is over quota." virtual_overquota_bounce = yes proxy_read_maps = $local_recipient_maps $mydestination $virtual_alias_maps $virtual_alias_domains $virtual_mailbox_maps $virtual_mailbox_domains $relay_recipient_maps $relay_domains $canonical_maps $sender_canonical_maps $recipient_canonical_maps $relocated_maps $transport_maps $mynetworks $virtual_mailbox_limit_maps smtpd_sender_restrictions = check_sender_access mysql:/etc/postfix/mysql-virtual_sender.cf smtpd_client_restrictions = check_client_access mysql:/etc/postfix/mysql-virtual_client.cf maildrop_destination_concurrency_limit = 1 maildrop_destination_recipient_limit = 1 virtual_transport = maildrop header_checks = regexp:/etc/postfix/header_checks 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 content_filter = amavis:[127.0.0.1]:10024 receive_override_options = no_address_mappings message_size_limit = 0 smtpd_delay_reject = yes smtpd_helo_restrictions = reject_invalid_hostname smtpd_helo_required = yes bounce_queue_lifetime = 1d maximal_queue_lifetime = 1d smtpd_timeout = 50s
