Dec 23 08:44:30 extranet postfix/smtp[24387]: F3443907: to=, relay=gmail-smtp-in.l.google.com[2a00:1450:400c:c06::1b]:25, delay=0.32, delays=0.02/0.01/0.19/0.11, dsn=5.7.1, status=bounced (host gmail-smtp-in.l.google.com[2a00:1450:400c:c06::1b] said: 550-5.7.1 [2001:41d0:1008:2b5a::] 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=IPv6AuthError for more information 550 5.7.1 . 196si30999080wmg.139 – gsmtp (in reply to end of DATA command))

To fix it add this on your main.cf postfix configuration file :
inet_protocols=ipv4

That’s all

The post Gmail & 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. appeared first on Agence de Développement Informatique du Nord.