Re: [Exim] Thoughts on sender/host verification.

On Wed, 19 May 2004, Matthew Byng-Maddick wrote:

> On Wed, May 19, 2004 at 01:36:58AM -0700, Scott Call wrote:
> This is basically the same as SPF, and has exactly the same set of problems.
>

Please expand on this statement, I'm curious about it.

My understanding of SPF is it sets an explicit (static, since it is
cached as part of DNS) list of hosts allowed to send mail for an entire
domain.

By changing the lookup to map an IP to an exact email address you get
increased granularity and you loose the server lock-in factor of SPF and
Domainkeys.

-Scott