Hi, I have an ISP Config 3 (latest stable version) installed on CentOS 6 following the perfect server guide. However when sending emails I get the following when sending to Gmail: relay=ASPMX.L.GOOGLE.COM[2a00:1450:400c:c06::1a]:25, delay=0.55, delays=0.04/0.05/0.12/0.35, dsn=5.7.1, status=bounced (host ASPMX.L.GOOGLE.COM[2a00:1450:400c:c06::1a] said: 550-5.7.1 [2a01:4f8:212:2495::2] Our system has detected that this message does 550-5.7.1 not meet IPv6 sending guidelines regarding PTR records and 550-5.7.1 authentication. Please review 550-5.7.1 https://support.google.com/mail/?p=ipv6_authentication_error for more 550 5.7.1 information This is because Postfix is sending with Localhost 127.0.0.1 in the headers. Result of postconf -n below alias_database = hash:/etc/aliases alias_maps = hash:/etc/aliases body_checks = regexp:/etc/postfix/body_checks broken_sasl_auth_clients = yes command_directory = /usr/sbin config_directory = /etc/postfix content_filter = amavis:[127.0.0.1]:10024 daemon_directory = /usr/libexec/postfix data_directory = /var/lib/postfix debug_peer_level = 2 header_checks = regexp:/etc/postfix/header_checks html_directory = no inet_interfaces = all inet_protocols = all mail_owner = postfix mailbox_size_limit = 0 mailq_path = /usr/bin/mailq.postfix manpage_directory = /usr/share/man message_size_limit = 0 mime_header_checks = regexp:/etc/postfix/mime_header_checks mydestination = server1.mydomain.co.uk, localhost, localhost.localdomain myhostname = server1.mydomain.co.uk mynetworks = 127.0.0.0/8 [::1]/128 myorigin = $myhostname nested_header_checks = regexp:/etc/postfix/nested_header_checks newaliases_path = /usr/bin/newaliases.postfix 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 queue_directory = /var/spool/postfix readme_directory = /usr/share/doc/postfix-2.6.6/README_FILES receive_override_options = no_address_mappings relay_domains = mysql:/etc/postfix/mysql-virtual_relaydomains.cf relay_recipient_maps = mysql:/etc/postfix/mysql-virtual_relayrecipientmaps.cf relayhost = sample_directory = /usr/share/doc/postfix-2.6.6/samples sendmail_path = /usr/sbin/sendmail.postfix setgid_group = postdrop smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd smtp_sasl_security_options = noanonymous smtp_tls_CAfile = /etc/pki/tls/certs/ca-bundle.crt smtp_tls_protocols = !SSLv2,!SSLv3 smtp_tls_security_level = may smtpd_client_message_rate_limit = 100 smtpd_client_restrictions = check_client_access mysql:/etc/postfix/mysql-virtual_client.cf smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination, check_recipient_access mysql:/etc/postfix/mysql-virtual_recipient.cf smtpd_sasl_auth_enable = yes smtpd_sasl_authenticated_header = yes smtpd_sasl_path = private/auth smtpd_sasl_type = dovecot smtpd_sender_restrictions = check_sender_access mysql:/etc/postfix/mysql-virtual_sender.cf smtpd_tls_cert_file = /etc/postfix/smtpd.cert smtpd_tls_key_file = /etc/postfix/smtpd.key smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3 smtpd_tls_protocols = !SSLv2,!SSLv3 smtpd_tls_security_level = may smtpd_use_tls = yes transport_maps = hash:/var/lib/mailman/data/transport-mailman, proxy:mysql:/etc/postfix/mysql-virtual_transports.cf unknown_local_recipient_reject_code = 550 virtual_alias_domains = virtual_alias_maps = hash:/etc/mailman/virtual-mailman, proxy:mysql:/etc/postfix/mysql-virtual_forwardings.cf, proxy:mysql:/etc/postfix/mysql-virtual_email2email.cf virtual_gid_maps = static:5000 virtual_mailbox_base = /var/vmail virtual_mailbox_domains = proxy:mysql:/etc/postfix/mysql-virtual_domains.cf virtual_mailbox_maps = proxy:mysql:/etc/postfix/mysql-virtual_mailboxes.cf virtual_transport = dovecot virtual_uid_maps = static:5000 Any help would be appreciated
Very unlikely that this is the cause as most mail servers with internal scanner have localhost in the headers for the internal scanning and they have no problems to send to gmail. The error message that you posted is not about localhost, it says that your IPv6 address is missing a PTR record.
Hi, These are the email headers for the mail that was sent: Return-Path: <[email protected]> Received: from server1.mydomain.co.uk (unknown [127.0.0.1]) by server1.mydomain.co.uk (Postfix) with ESMTP id 908DF2340340 for <[email protected]>; Fri, 2 Sep 2016 15:06:26 +0000 (UTC) X-Virus-Scanned: amavisd-new at server1.mydomain.co.uk Received: by server1.mydomain.co.uk (Postfix, from userid 48) id 91204234034E; Fri, 2 Sep 2016 17:06:25 +0200 (CEST) Received: from {IP ADDRESS} (SquirrelMail authenticated user [email protected]) by with HTTP; Fri, 2 Sep 2016 15:06:25 -0000 Message-ID: <ed14f546a37966ce5791939cf8f9fd15.squirrel@www.brilliantmoney.co.uk> Date: Fri, 2 Sep 2016 15:06:25 -0000 Subject: test From: [email protected] User-Agent: SquirrelMail/1.4.22-4.el6 MIME-Version: 1.0 Content-Type: text/plain;charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-Priority: 3 (Normal) Importance: Normal I think Google is trying to retrieve a PTR record for 127.0.0.1 which is why I am getting this error
No, your problem is not related to the localhost lines in any way. Googles error message is clear and it refers to a missing PTR record for the external IPv6 address of your server. Yes, the reason is the missing IPv6 PTR record of your external IPv6 IP address as google pointed out in the error message that you posted above. Regarding the localhost line for your server name, that is most likely a problem in your /etc/hosts file. ensure that your server hostname is listed there only with your external IP, not for 127.0.0.1
