We recently (within the last two weeks) started getting a very large number of logs like this:
postfix/smtpd[29456]: lost connection after RCPT from cel-broadband1-ws-72.dsl.airstreamcomm.net[64.33.198.73] After doing packet traces it appears that the client is sending RST packets to our server, which doesn't make any sense? Here is postconf -n: alias_database = hash:/etc/aliases alias_maps = hash:/etc/aliases anvil_rate_time_unit = 60s bounce_queue_lifetime = 3d broken_sasl_auth_clients = yes command_directory = /usr/sbin config_directory = /etc/postfix daemon_directory = /usr/libexec/postfix debug_peer_level = 9 default_destination_recipient_limit = 1000 default_process_limit = 1000 header_checks = regexp:/etc/postfix/header_checks html_directory = no inet_interfaces = all mail_owner = postfix mailbox_size_limit = 52224000 mailq_path = /usr/bin/mailq.postfix manpage_directory = /usr/share/man maximal_queue_lifetime = 3d message_size_limit = 52224000 mydestination = $myhostname, localhost.$mydomain, localhost myhostname = osmtp-1.airstreamcomm.net mynetworks = $config_directory/mynetworks newaliases_path = /usr/bin/newaliases.postfix queue_directory = /var/spool/postfix readme_directory = /usr/share/doc/postfix-2.3.3/README_FILES recipient_bcc_maps = hash:/etc/postfix/recipient_bcc relayhost = omrcd1.parcel-airstreamcomm.net sample_directory = /usr/share/doc/postfix-2.3.3/samples sender_bcc_maps = hash:/etc/postfix/sender_bcc_jatheon sendmail_path = /usr/sbin/sendmail.postfix setgid_group = postdrop smtp_connect_timeout = 5m smtp_data_done_timeout = 900s smtp_data_init_timeout = 900s smtp_data_xfer_timeout = 900s smtp_helo_timeout = 900s smtp_mail_timeout = 900s smtp_tls_note_starttls_offer = yes smtpd_client_event_limit_exceptions = static:all smtpd_helo_required = yes smtpd_recipient_restrictions = permit_mynetworks, check_recipient_access hash:/etc/postfix/restricted_recipients check_client_access hash:/etc/postfix/popimap_access, permit_sasl_authenticated, reject_unauth_destination smtpd_sasl_auth_enable = yes smtpd_sasl_path = private/auth-client smtpd_sasl_security_options = noanonymous smtpd_sasl_type = dovecot smtpd_sender_restrictions = reject_unknown_sender_domain, reject_non_fqdn_sender, permit smtpd_timeout = 180s smtpd_tls_auth_only = no smtpd_tls_cert_file = /etc/pki/tls/certs/postfix.crt smtpd_tls_key_file = /etc/pki/tls/private/postfix.key smtpd_tls_loglevel = 1 smtpd_tls_received_header = yes smtpd_tls_security_level = may smtpd_tls_session_cache_database = btree:/var/spool/postfix/smtpd_tls_cache smtpd_tls_session_cache_timeout = 3600s tls_random_source = dev:/dev/urandom transport_maps = hash:/etc/postfix/transport unknown_local_recipient_reject_code = 550
