I’m having a lot of problems with Gmail. Some email can’t be delivered:
[2a01:7c8:d001:139:5054:ff:fec0:769e] Our system has detected that
this message does not meet IPv6 sending guidelines regarding PTR
records and authentication. Please review
https://support.google.com/mail/?p=IPv6AuthError for more information. by17si6234894ejb.604 - gsmtp (in reply to end of DATA command)
Any help on this?