SMTP over IPv6 : gmail classifying nearly all IPv6 mail as spam since 20140818

[Laurent GUERBY]

Hi,

We've been running SMTP over IPv6 with postfix successfully for over a
year and since 20140818 gmail.com IPv6 MX started to classify most IPv6
sourced emails sent from our machine to @gmail.com as spam. The exact
same message sent using IPv4 within one minute of the IPv6 bounce is
accepted.

As there's no way to reach google mailops we had to remove IPv6 from our
mail machines and go back to IPv4 only for mail, which is sad.

Are we alone with this recent experience?

Sincerely,

Laurent