On Thu, Oct 10, 2013 at 01:58:45AM +0200, Dominik George wrote:
> > Confirmed, Postfix looks at the answer section only. Claims to
> > the contrary are based on false speculation.
>
> Hmm, that leads us to the original question:
>
> Why does postfix sometimes not find the AAAA record for any given MX?
It does not fail to find it. It just uses IPv4. See:
http://www.postfix.org/postconf.5.html#smtp_address_preference
The documentation for
http://www.postfix.org/postconf.5.html#inet_protocols
is sadly I believe out of date. The sentence:
When both IPv4 and IPv6 support are enabled, the Postfix SMTP
client will attempt to connect via IPv6 before attempting to
use IPv4.
is no longer accurate. That is only true when
smtp_address_preference = ipv6
The correct description is:
When both IPv4 and IPv6 support are enabled, the Postfix SMTP
client, for Postfix versions prior to 2.8, will attempt to
connect via IPv6 before attempting to use IPv4. Starting
with 2.8 protocol preference is controlled via the new
smtp_address_preference parameter.
--
Viktor.
