Marat Khalili:
> Postfix is installed as forwarder to a fixed relay in a system with no
> IPv6 addresses (disabled system-wide by net.ipv6.conf.*.disable_ipv6
> lines in sysctl). Still, for each message it separately requests both A
> and AAAA records of the relay from DNS, as I verified by tcpdump. Is it
> a bug or feature? (Yes I know I can explicitly disable IPv6 in postfix
> configuration too, but that's not the point.)
Postfix from me installs with IPv6 turned off. Complain with your
distributor if they change that.
Wietse
> My investigation actually started with the following lines in mail.log,
> which may or may not be related:
>
> > May 4 07:52:16 postfix postfix/scache[1518]: statistics: domain
> > lookup hits=0 miss=3 success=0%
>
> (3 messages were sent in this interval; there are always 0 hits and 0%
> success rate.)
>
> I'm using Postfix 3.1.0-3 under Ubuntu 16.04. Relay is secure.emailsrvr.com.
>
> --
>
> With Best Regards,
> Marat Khalili
>
