[192470] in North American Network Operators' Group
Re: IPv6 automatic reverse DNS
daemon@ATHENA.MIT.EDU (Steve Atkins)
Fri Oct 28 21:40:24 2016
X-Original-To: nanog@nanog.org
From: Steve Atkins <steve@blighty.com>
Date: Fri, 28 Oct 2016 18:37:25 -0700
To: NANOG list <nanog@nanog.org>
In-Reply-To: <1477703043.2229.439.camel@biplane.com.au>
Errors-To: nanog-bounces@nanog.org
> On Oct 28, 2016, at 6:04 PM, Karl Auer <kauer@biplane.com.au> wrote:
>
>> 1b) anti spam filters believe in the magic of checking
>> forward/reverse match.
>
> Someone in this thread said that only malware-infested end-users are
> behind IP addresses with no reverse lookup. Well - no. As long as we
> keep telling anyone who isn't running a full-bore commercial network to
> "consume, be silent, die", we are holding everyone back, including
> ourselves.
If you send mail over IPv6 from an address with no reverse DNS you
will see quite a lot of this sort of thing:
550 5.7.1 [*] Our system has detected that this message
5.7.1 does not meet IPv6 sending guidelines regarding PTR records and
5.7.1 authentication. Please review
5.7.1 https://support.google.com/mail/?p=ipv6_authentication_error for more
5.7.1 information.
>
> It's fine to use no-reverse-lookup as a component of a spamminess
> score. It's not OK to use it as proof of spamminess.
People running large mailservers made that decision some time
ago. Disagreeing with them won't make them accept your email.
Cheers,
Steve
