Applicable to:
- Plesk for Linux
Symptoms
-
Plesk server has IPv6 address. When an email message is sent from a Plesk server to a Gmail account, it fails to be delivered.
-
The following error message appears in
/var/log/maillog:CONFIG_TEXT: ipv6_failed_after_I_sent_the_message./Remote_host_said:_550-5.7.1_[ipv6______16]_Our_system_has_detected_that_this/550-5.7.1_message_does_not_meet_IPv6_sending_guidelines_regarding_PTR_records/550-5.7.1_and_authentication._Please_review/550-5.7.1_https://support.google.com/mail/?p=ipv6_authentication_error_for_more/550_5.7.1_information._hg7si388602wjb.61_-_gsmtp/
-
The sender receives an email with following message:
CONFIG_TEXT: Remote host said: 550-5.7.1 [2a00:14e8:211:2123::2 16] Our system has detected that this
550-5.7.1 message does not meet IPv6 sending guidelines regarding PTR records
550-5.7.1 and authentication. Please review
550-5.7.1 https://support.google.com/mail/?p=ipv6_authentication_error for more
550 5.7.1 information. la8si618732wjb.94 - gsmtp
Cause
Gmail Guidelines for IPv6 are not met: the IPv6 address does not have a PTR record.
Resolution
Solution I: Contact your hosting provider to set up a reverse DNS for IPv6 address.
Solution II: Apply one of the following instructions:
-
Connect to the Plesk server via SSH.
-
Find out which protocols are currently enabled with the command:
# postconf inet_protocols
inet_protocols = all -
If the output is the same, modify Postfix configuration file
main.cfby executing the command below:# postconf inet_protocols=ipv4
-
Restart Postfix to apply the changes:
# service postfix restart
-
Verify the changes:
# postconf inet_protocols
inet_protocols = ipv4
-
-
Go to Tools & Settings > IP Addresses > click on the Sites number next to IPv6. If there are domains hosted on IPv6, go to Domains > example.com > Web Hosting Access and switch these domains to IPv4 only.
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When you are sure no domains are using IPv6 in Plesk, connect to the Plesk via SSH and open the file
/etc/sysctl.confin a text editor. In this example, we are using the vi editor:# vi /etc/sysctl.conf
-
Add the following lines:
# grep ipv6 /etc/sysctl.conf
net.ipv6.conf.all.disable_ipv6=1
net.ipv6.conf.default.disable_ipv6=1 -
Apply the changes with the following command:
# sysctl -p
-
Remove IPv6 addresses from Plesk: Click Reread IP at Tools & Settings > IP Addresses.
Comments
2 comments
tried the workaround (Configuring mail server to use IPv4 only (Postfix))
and getting this.
: host gmail-smtp-in.l.google.com[74.125.24.26] said:
550-5.7.1 [202.187.73.217] The IP you're using to send mail is not
authorized to 550-5.7.1 send email directly to our servers. Please use the
SMTP relay at your 550-5.7.1 service provider instead. Learn more at 550
5.7.1 https://support.google.com/mail/?p=NotAuthorizedError
b23si1667962pls.67 - gsmtp (in reply to end of DATA command)
Hello kihoshi
Please, check the article specified in the error message: https://support.google.com/mail/answer/10336?p=NotAuthorizedError&visit_id=637357723079341012-855674621&rd=1
The article described why emails from your IP are refused and how to avoid it.
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