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

[🔓Dan Wing]

On Aug 22, 2014, at 7:42 AM, Matthew Huff <mhuff at ox.com> wrote:

> Currently it is not feasible to do ipv6 reputation filtering. IPv4 reputation filtering is a big part of most anti-spam engines, so without it, SPF / DKIM of domain reputation is the best alternative.
> 
> BTW, we have had to remove all IPv6 from our mail gateways due to the large number of Exchange SBS with broken isatap/6to4 tunnels causing mail to blackhole.

MTU issue?

-d


> These have been at small web based retailers which don't have hosted email. After the third incident, we yanked our IPv6 from our MX/gateways.
> 
> 
> 
> ----
> Matthew Huff             | 1 Manhattanville Rd
> Director of Operations   | Purchase, NY 10577
> OTA Management LLC       | Phone: 914-460-4039
> 
> -----Original Message-----
> From: ipv6-ops-bounces+mhuff=ox.com at lists.cluenet.de [mailto:ipv6-ops-bounces+mhuff=ox.com at lists.cluenet.de] On Behalf Of Nick Hilliard
> Sent: Friday, August 22, 2014 10:25 AM
> To: Lorenzo Colitti; Laurent GUERBY
> Cc: IPv6 Ops list
> Subject: Re: SMTP over IPv6 : gmail classifying nearly all IPv6 mail as spam since 20140818
> 
> On 22/08/2014 15:16, Lorenzo Colitti wrote:
>> Are you following the "Additional guidelines for IPv6" section of
>> https://support.google.com/mail/answer/81126 ?
> 
> Lorenzo,
> 
> it looks like Google is trying to enforce SPF / DKIM on ipv6 connections 
> where there is no similar requirement for ipv4.  Is there a particular 
> reason for this?  It's causing a lot of breakage.
> 
> Nick
>