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Re: [ietf-dkim] New Issue: Applicability of SSP to subdomains

2006-12-07 21:35:55
Doug,

I'm really confused by your reply. The question is simply, "should it be possible for an SSP record published by example.com to also apply to sub.example.com [for any value of sub]". I don't see how it relates to EAI, annotation, and so forth.

I interpret your response as expressing the position that this should not be a requirement. Let me know if I have that wrong.

-Jim

Douglas Otis wrote:

On Dec 7, 2006, at 2:46 PM, Jim Fenton wrote:

I'd like to bring up this topic again, which I raised on November 9 and got only a little discussion and didn't make it into the issue tracker. The various drafts that have been proposed for SSP differ substantially in how they address subdomains, and I'd still like to understand whether this is an SSP requirement or not.

This concern incorrectly assumes protection is afforded as a type of prohibition. Such a prohibition fails with respect to EAI, as this eliminates reliance upon visual inspection, as well as changing headers viewed by the recipient.

When the protection afforded by DKIM is abased upon an annotation of the "recognized" email-addresses "associated" with a valid signature, then there is _no_ need to have policy be associated with sub-domains. There is also _no_ need to search for policy either. Without an "associative" mechanism, the message simply does not receive any annotation. Nothing is blocked, but then nothing gets annotated either.

DKIM requires some form of annotation as the signature is invisible by design. The "recognition" of the email-address should be based upon actual email-addresses comparisons that have been previously retrained by the recipient. These retained email-addresses might be in the form of an address-book or a DAC compatible list.

It is hard to imagine chasing 2 million new domains every day. It does not matter what policy is required, or what hoops bad actors jump through, they will not be limited by these requirements. Just the opposite. Nor will reliance upon visual examination offer any protection either. Just the opposite. There is a large part of the world that does not even use ASCII email-addresses. : )

-Doug
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