[mail-vet-discuss] SHOULD the header be signed?

[Murray S. Kucherawy]

This came up both at the last IETF and at this one, so I thought it 
worth opening up here once before I submit the draft to the area director.

Should the normative text in the draft specify that this header SHOULD 
be signed?

The point comes from someone who operates in an environment in which he 
doesn't necessarily want to trust that the border MTAs are properly 
removing forged A-R headers.  This would mean there needs to be a shared 
or distributed secret between the border MTAs where the header is added 
and the clients where the header will be used.  It also means I'd either 
have to reference a header signing/verifying mechanism or define one.

Some of the risk of this is mitigated by the AUTHRES ESMTP extension 
draft, but the time to implement there is going to be longer than the 
support for this header.

The hallway track at the last IETF and since was that the current 
draft's Section 8.1 (especially the last paragraph) provide sufficient 
discussion of this issue.  I might change "posted" to "posted or shared".

What are the list's opinions?