[ietf-dkim] Scalability concerns with Designated Signing Domains

[Douglas Otis]

On Sat, 2006-08-26 at 08:18 -0700, william(at)elan.net wrote:
> I've proposed before that in case of large number of domains SPF-like
> macro expansion be allowed in place of actual domain.

Bad idea and not needed.  To scale into the tens of thousands, just
prefix the queried domain above the policy label and use wildcards
within this isolated namespace to answer the query.  Zero macros are
required and the answer and the query remain small.

-Doug