Google bouncing mail with IPV6 PTR error
Problem reported by Devang Shah - November 3, 2015 at 7:24 AM
users are facing issue when sending mails to GMAIL users since last few days
Could not deliver message to the following recipient(s):
Failed Recipient: spandey2402 @ gmail com
Reason: Remote host said: 550 5.7.1 [2002:d80c:d632::d80c:d632] Our system has detected that this message
5.7.1 does not meet IPv6 sending guidelines regarding PTR records and
5.7.1 authentication. Please review
5.7.1  https : // support.google com/mail/? p=ipv6_authentication_error for more
5.7.1 information. k12si41115297pbq.64 - gsmtp
   -- The header and top 20 lines of the message follows --
IPv4 RDNS & PTR are all fine & no change has been made & i am not using IPv6 yet 
Server is working fine since last 2 years
i am using SM 11.7 Entp edition
any help will be useful

2 Replies

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Bruce Barnes Replied
November 3, 2015 at 8:37 AM
When you originally setup your SmarterMail server with your IPV4 e-mail addresses, you setup an rDNS for the fully qualified domain name of the server.
From the error message, it appears that you have not properly setup an rDNS for your new IPV6 IP address.
Once you do that, and update your FEEDBACK LOOPS with YAHOO and the other providers, these errors should stop.
IPV6 is so new that this is a commonly overlooked error.
If you have SmarterMail upgrade protection, you will probably want to consider upgrading your software to 11.4.5784, which was released last night and contains some very significant security updates.
It also handles DMARC, DKIM, SPF and other things which are now very important to ensure e-mail is accepted by everyone.
Here's a link to the latest features and fixes contained in SmarterMail 14.4.5784:

Bruce Barnes
ChicagoNetTech Inc

Phone: (224) 444-0169

E-Mail and DNS Security Specialist
Network Security Specialist

Customer Service Portal: https://portal.chicagonettech.com
Website: https://www.ChicagoNetTech.com
Security Blog: http://networkbastion.blogspot.com/

Web and E-Mail Hosting, E-Mail Security and Consulting
Devang Shah Replied
November 4, 2015 at 6:47 AM
Dear Bruce,
I couldn't find any release of 11.4.5784 for SM 11.x version as u have mentioned 
Can u send me DL link if i am missing it?

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