[ietf-dkim] Expiration Tag (x=) is required to minimize DNS lookups.

[Mark Delany]

On Tue, Apr 18, 2006 at 06:39:49AM -0400, Hector Santos allegedly wrote:
> Summary:
> 
>    x= is needed to offer a major DKIM verifier optimization to
>    address expiring or revoked keys.

This is surely an edge case that Knuth warns us about.


Mark.