On Wed, 9 Jun 2004, Mark Shewmaker wrote:
To get the same result with current SPF1 (albeit uglier and less efficient),
you can use multiple exists queries.
I believe you'd have to write a single, very complex, difficult-to-parse
exist _mechanism_, (ie, "exists:blah") so the whole shebang can pass or
fail at one go.
That also complicates the DNS server work on the sending side. (And it
makes it more difficult to outsource things like SES verification to
other DNS providers.)
The point of generalized 'exists' is that you have one exist mechanism
which contains all macros. A scripted DNS server then responds to
the query with whatever code the sender desires. Using a static DNS
server would be more difficult - as you note. A static DNS server is
feasible provided there is a reasonably small enumeration of all
pass results which can be updated periodically.
Think of the exists DNS server like a CGI/Servlet/Snakelet/ASP web page
compared to a static web page.
--
Stuart D. Gathman <stuart(_at_)bmsi(_dot_)com>
Business Management Systems Inc. Phone: 703 591-0911 Fax: 703 591-6154
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