Viktor Dukhovni:
> On Mon, Jun 16, 2014 at 09:12:18AM +0200, Erwan David wrote:
>
> > I do not know whether there is a email server there, but dk. has a A
> > record, thus user@dk might be a valid email address...
>
> Though "technically" valid, it is in practice unusable. Almost
> all senders will rewrite this to <user@dk.$senders_domain>. Getting
> the whole world to disable short hostnames is a quixotic exercise.
It's not just a problem with email. ssh appends the domain,
web browsers append the domain, just to name a few.
That said, you can disable such behavior with Postfix 2.8 and later:
/etc/postfix/main.cf:
append_dot_mydomain = 0
# The following is the default:
# smtp_dns_resolver_options =
For Postfix there is no need to meddle with res_defnames or res_dnsrch
options in /etc/resolv.conf, because Postfix already ignores those.
Wietse
