On 16 Jun 2014, at 17:22, Viktor Dukhovni <postfix-us...@dukhovni.org> wrote:
> 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. IMHO, adding A or MX records in a root zone testifies to a lack of understanding of DNS as an interconnected system. One just really shouldn't, even though it is technically correct. Saw this last week, as another example, a list of TLDs with MX records defined; https://gist.github.com/ddol/1445736 And then there's user confusion; http://dk. While the above works for me, I reckon that quite a few users will perceive this as incomplete, like someone forgot to add 'com' at the end. In other words, if you do run a TLD of any kind, do us all a favour, and admit that it's unlikely that it'll ever go beyond a neat trick that few people will understand. Just leave them out of your root zone. Mvg, Joni
