[ietf-dkim] domain existence check

[Eric Allman]

I remain convinced that it is absolutely essential to retain the 
existence check.  Making it advisory would be a serious mistake.

eric

--On May 22, 2008 4:03:28 PM +0000 John Levine <johnl at iecc.com> wrote:

> We don't seem to have resolved the question of whether the ADSP
> should define a specific existence check, or just say that you
> should check but leave the definition for other places.
>
> Personally, I think it's severe mission creep to try to define an
> existence check.  It's straightforward to check for a NXDOMAIN or
> NODATA result, but I see no reason to think that such a check has
> the semantics an ADSP user would want.
>
> To touch on some of the issues (and try not to rehash them all), the
> majority of A and AAAA records don't name domains used in mail and
> you can't check short of sending a test message and waiting a week
> to see if it bounces, there's many ways a name can exist but again
> not for mail (what if there's just a TXT record), and any check we
> defined would just be wrong if, e.g., next year we make MX . the
> no-mail standard.
>
> So I like Arvel and Wietse's approach, say to do it but don't try to
> define it since any definition would be wrong.  Other thoughts?
>
> R's,
> John