I moved our company over to postfix (v2.6.2) last Friday and have been mesmerized by the log. One thing I'm seeing is a lot of 'lost connections from unknown[ IP ]'. I'm hoping that these are due to either poorly written spambots bailing early or smtpd_recipient_restrictions rejecting the connection.
google finds discussions about it but I couldn't find anything really recent. From the following can you determine if this is something I should be worried about? I'd be happy to provide more or different log data if required. $ grep 'lost connection' /var/log/mail.log <snip> Mar 30 05:07:14 mail postfix/smtpd[45236]: lost connection after DATA from unknown[123.28.125.3] Mar 30 05:07:17 mail postfix/smtpd[45244]: lost connection after DATA from unknown[62.32.223.28] Mar 30 05:07:18 mail postfix/smtpd[45240]: lost connection after RCPT from public16037.xdsl.centertel.pl[79.163.62.165] Mar 30 05:07:18 mail postfix/smtpd[45159]: lost connection after RCPT from unknown[218.157.167.131] Mar 30 05:07:20 mail postfix/smtpd[45188]: lost connection after CONNECT from unknown[212.63.221.10] Mar 30 05:07:23 mail postfix/smtpd[45230]: lost connection after RCPT from mproxy01.jheel.bdcom.com[210.4.76.3] Mar 30 05:07:25 mail postfix/smtpd[45229]: lost connection after DATA from unknown[119.15.93.218] Mar 30 05:07:27 mail postfix/smtpd[45237]: lost connection after RCPT from unknown[213.198.111.207] <snip> Most are unknown: $ grep 'lost connection' /var/log/mail.log | wc -l 9178 $ grep 'lost connection after RCPT from unknown' /var/log/mail.log | wc -l 2758 $ grep 'lost connection after DATA from unknown' /var/log/mail.log | wc -l 3507 $ grep 'lost connection after CONNECT from unknown' /var/log/mail.log | wc -l 237 $ postconf -n broken_sasl_auth_clients = yes command_directory = /opt/local/sbin config_directory = /opt/local/etc/postfix daemon_directory = /opt/local/libexec/postfix data_directory = /opt/local/var/lib/postfix debug_peer_level = 2 default_privs = nobody delay_warning_time = 4h home_mailbox = Maildir/ html_directory = no mail_owner = _postfix mailq_path = /opt/local/bin/mailq manpage_directory = /opt/local/share/man mydestination = $myhostname, localhost.$mydomain, localhost myhostname = mailbox.dop.com mynetworks = 192.168.0.0/23, 127.0.0.0/8 myorigin = $mydomain newaliases_path = /opt/local/bin/newaliases proxy_interfaces = 70.167.15.114 queue_directory = /opt/local/var/spool/postfix readme_directory = /opt/local/share/postfix/readme sample_directory = /opt/local/share/postfix/sample sendmail_path = /opt/local/sbin/sendmail setgid_group = _postdrop smtpd_banner = $myhostname ESMTP $mail_name smtpd_enforce_tls = no smtpd_helo_required = yes smtpd_recipient_restrictions = permit_sasl_authenticated, permit_mynetworks, reject_non_fqdn_sender, reject_non_fqdn_recipient, reject_unknown_sender_domain, reject_unknown_recipient_domain, reject_unauth_pipelining, reject_unauth_destination, reject_unlisted_recipient, check_helo_access hash:/opt/local/etc/postfix/helo_checks, check_sender_access hash:/opt/local/etc/postfix/access_sender, reject_rbl_client zen.spamhaus.org, reject_rbl_client bl.spamcop.net, check_policy_service inet:127.0.0.1:60000, check_client_access pcre:/opt/local/etc/postfix/dspam_filter_access smtpd_reject_unlisted_sender = yes smtpd_sasl_auth_enable = yes smtpd_sasl_local_domain = $myhostname smtpd_sasl_path = private/auth smtpd_sasl_security_options = noanonymous smtpd_sasl_type = dovecot smtpd_sender_restrictions = permit_mynetworks, reject_unknown_address smtpd_tls_cert_file = /opt/local/etc/postfix/ssl/certs/postfix.cert smtpd_tls_key_file = /opt/local/etc/postfix/ssl/private/postfix.key smtpd_tls_loglevel = 1 smtpd_use_tls = yes tls_random_source = dev:/dev/urandom unknown_local_recipient_reject_code = 550 virtual_alias_maps = mysql:/opt/local/etc/postfix/mysql_virtual_alias_maps.cf virtual_gid_maps = static:102 virtual_mailbox_base = /Volumes/mail/vmail/ virtual_mailbox_domains = mysql:/opt/local/etc/postfix/mysql_virtual_mailbox_domains.cf virtual_mailbox_maps = mysql:/opt/local/etc/postfix/mysql_virtual_mailbox_maps.cf virtual_minimum_uid = 102 virtual_transport = dovecot virtual_uid_maps = static:102 -Terry
