[ietf-dkim] The URL to my paper describing the DKIM policy options

[Steve Atkins]

On Jul 26, 2006, at 1:04 PM, Hector Santos wrote:

>
> ----- Original Message -----
> From: "Steve Atkins" <steve at blighty.com>
>
>
>> "MX 0 ." seems to be the standard way of asserting that a domain
>> neither sends nor receives email. Shoehorning the same assertion
>> into multiple different pseudo-standards simply leads to  
>> contradiction.
>
> MX is about INBOUND. Not Outbound Mail.  That would only cover a  
> possible
> "no don't receive mail" policy. But I doubt this MX 0 is widely  
> supported.
> The attempts I have researched shows very low usage and if found,  
> it is
> mixed used with other non MX 0 statements.  I hope this does not  
> begin to
> chip away at SSP.
>
>> I don't see why people would pay any more attention to an SSP
>> statement of such than they do to SPF statements of it. Just the
>> opposite, shoehorning unneeded cruft into SSP makes it less likely
>> that people will pay any attention to it, I'd think.
>
> Steve, the SPF example was just an example to Stephen, that such a "No
> (Outbound) Mail expected" concept does exist and is used in  
> practice.  If
> AltaVista.com can do it, so can others.

     [steve at goliath steve]$ host -t mx altavista.com
     altavista.com mail is handled by 0 .

My point exactly. But even ignoring that option and just
comparing to SPF...


> I can tell you that we will add a
> NO MAIL POLICY to atleast 3-4 of our own domains if SSP was to  
> become part a
> new wide adopted practice.   We have no problem protecting local  
> policy when
> the spoofs come out way.  It is to expose to the external world not to
> expect and accept such spoofs.

There is no need to tie "signing of email" to "this domain
sends no email". As such it's not something that _has_ to
be in SSP (unlike "We send no non-signed email"). If you
believe SSP has value you pretty much have to believe
the same of SPF, and SPF already supports making that
statement.

So the only advantage of supporting "we send no mail"
in SSP would be if you believe that the set of people who
look at SSP and do not look at SPF is noticably non-zero.

That's not a reason not to add support for this to SSP, though,
as long as you recognize that it's just adding a redundant
way of saying the same thing at the cost of a small increase
in complexity and risk of contradictory policy messages
via different communication channels.

Cheers,
   Steve