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

Laurent GUERBY laurent at
Fri Aug 22 09:56:55 CEST 2014


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

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?



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