[ietf-dkim] Are subdomains like parent domains?

[John Levine]

>I think I'm not the only one making assumptions here.

Of course not.

I'm honestly trying to figure out whether any mail systems treat mail
from sub.foo.com as being from foo.com when they make decisions about
sorting, filtering, and so forth.  That's why I'd really appreciate
some actual examples if there are any.  I'm not trying to be
confrontational here, I'm trying to gather data.

As far as I can tell, nobody does, but the whole issue of the tree
walk is predicated on this assumption.  If the assumption is indeed
untrue, the treewalk (in any of its varieties) serves no purpose and
we can just get rid of it.

R's,
John