[prev in list] [next in list] [prev in thread] [next in thread] 

List:       postfix-users
Subject:    Re: Google rejecting IPv6 mails
From:       wietse () porcupine ! org (Wietse Venema)
Date:       2013-10-10 0:24:56
Message-ID: 3cwCjh6PK6zjymp () spike ! porcupine ! org
[Download RAW message or body]

Patrick Lists:
> On 10/10/2013 01:37 AM, Wietse Venema wrote:
> > James Cloos:
> >> Unfortunately it is not uncommon with v6.
> >>
> >> I've had to whitelist a number of sites over the last year where the
> >> outoing mta added a v6 address w/o a ptr.
> >>
> >> Mostly it appeared to be due to new v6 routes and autoconfig surprising
> >> the mta admins.
> >
> > I wonder how this could happen, as Postfix still installs with IPv6
> > turned off. Unless, of course, distributors have removed my temporary
> > safety net that disables IPv6 for the time being.
> 
> Not sure if that's what you mean but a quick check of main.cf in the 
> postfix 2.10.2 RPM for F19 and postfix 2.6.6 RPM for CentOS 6.4 shows:
> 
> # Enable IPv4, and IPv6 if supported
> inet_protocols = all

Damned morons. They break Postfix for sites that have IPv4 only (*)
and they cause bad PTR problems for sites that turn on IPv6 as
discussed on this list.

(*) Postfix looks up a *limited* number of IP addresses, and if a site
has lots of IPv6 addresses, then Postfix may end up trying only one
IPv4 addresses.

	Wietse
[prev in list] [next in list] [prev in thread] [next in thread]