On 3/1/2023 6:12 AM, Douglas Foster wrote:

> A sub-issue to consider:   Should we do a Tree Walk on the authenticating 
> domain?
> For example, assume that "virgina.gov <http://virgina.gov>" and 
> "dmas.virginia.gov <http://dmas.virginia.gov>" both have DMARC policies with 
> relaxed alignment.   Should "dmas.virginia.gov <http://dmas.virginia.gov>" be 
> prohibited from authenticating "virginia.gov <http://virginia.gov>"?
> My gut says yes, but it adds some overhead to enforce that rule.

My gut says that might break ESPs who are using subdomains for SPF relaxed 
alignment. Unless you are saying that it's safe for treewalk changes to break 
MAILFROM=bounces.dmas.virginia.gov rfc5322.From=virginia.gov, then maybe there 
is some data to suggest that it is rare.

Dare I suggest that virginia.gov be able to define the subdomains to which SPF 
relaxed alignment should apply? As a domain owner, I might be inclined to 
reserve something like bounces.virginia.gov for all MAIL FROM sub-sub-domains 
that are used for delegating ESP traffic and manage it similar to DKIM 
selectors. aspf=s for any subdomains that aren't otherwise defined.

In my experience talking to state governments (as well as reflecting back on my 
own time in state government), domain owners are seeing a lot of ESP usage 
sprawl among their sub-domains/agencies/departments and they are frustrated 
that they can't manage or govern it effectively. In this late stage of the 
game, they won't be able to publish aspf=s to keep agencies from delegating ESP 
usage of virginia.gov when the domain owner would otherwise not want them to.

Jesse
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