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

Lorenzo Colitti lorenzo at
Fri Aug 22 16:16:04 CEST 2014

On Fri, Aug 22, 2014 at 12:56 AM, Laurent GUERBY <laurent at> wrote:

> We've been running SMTP over IPv6 with postfix successfully for over a
> year and since 20140818 IPv6 MX started to classify most IPv6
> sourced emails sent from our machine to 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 you following the "Additional guidelines for IPv6" section of ?
-------------- next part --------------
An HTML attachment was scrubbed...

More information about the ipv6-ops mailing list