[ietf-dkim] more on discardable, was Lists "BCP" draft

[Steve Atkins]

On May 24, 2010, at 6:38 PM, John Levine wrote:

>>> Refusing signups from those domains is probably a bit extreme, though.
>> 
>> What about a warning at signup time if a "discardable" ADSP record is
>> found for the registrant's domain?
> 
> That doesn't help.  In the IETF's scenario, domain A sent mail which
> was marked discardable to the list, and recipients at domain B were
> rejecting it and the people at B got bounced off the list.  I'd have
> to squint awfully hard to come up with an argument that it is wrong to
> reject unsigned discardable mail at SMTP time.

I think that Murray was suggesting that in addition to rejecting all
mail from domain A it would be polite to also warn anyone from
domain A who subscribes to the list that their mail would be
rejected (which seems good UX design to me).
> 
> Since ADSP causes problems for innocent bystanders, I think it's
> reasonable to decline A's mail in the first place.  This is doubly
> true since the ADSP RFC rather specifically says that you shouldn't
> mark a domain discardable if its users send mail to lists.

It causes no problems at all to innocent bystanders in that case - the
recipient at domain B is a willing participant who has chosen both
to pay attention to ADSP and to respond to it by rejecting, rather than
discarding, mails labeled "discardable". 

Cheers,
  Steve