Gmail rejecting or blocking emails via SMTP : The sender does not meet basic ipv6 sending guidelines of authentication and rdns resolution of sending ip. Please review https://support.google.com/mail/answer/81126for more information.
Found this on my Poundhost server when trying to send emails to Gmail – “The sender does not meet basic ipv6 sending guidelines of authentication and rdns resolution of sending ip. Please review https://support.google.com/mail/answer/81126for more information.” Strangely, turned out to