[ietf-dkim] user level ssp

[Douglas Otis]

On Sep 6, 2006, at 3:44 PM, Jim Fenton wrote:

> The aspect of user-level SSP that concerns me equally is the  
> transaction load.  When user-level SSP is "turned on", the verifier  
> MUST query for a user-level record in addition to the domain-level  
> record.  User-level queries are not as effectively cached, since  
> these are queries for individual addresses, not domains.

This depends upon the number of exceptions made, and whether these  
exceptions can normally be handled within the domain level  
transaction.  If this mechanism is intended to provide additional  
assurances by way of added annotations for a few email-addresses, it  
seems likely this could be accommodated within a domain level  
transaction.

-Doug