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