[ietf-dkim] Is accountability binary?

[Hallam-Baker, Phillip]

> What that suggests then is that as a recipient implementing 
> local decisions you may want to know both the accountable 
> forwarder and the accountable origin. Is that a reasonable inference?
> 
> First Question: Must DKIM provide both of these pieces of 
> information to you?
> 
> Second question: Do you really truly care about the forwarder 
> or is that more an artifact of today's world where it's hard 
> to look beyond the forwarder?

To determine whether or not something is spam all I need is to know that
someone in the path is able to vouch for it. Who that is I don't really
care.

As to whether accountability is binary or not, of course there are
shades of grey. There is always going to be a probability that the party
cannot be held accountable.

What really matters is the would-be defaulter's expectation of
accountability. Most criminals will risk a perceived 5% chance of being
caught, few will risk a 95% chance. But it's the perception that
matters.