--On Samstag, September 03, 2005 16:58:20 -0700 Gaven Henderson
<Gaven(_at_)GavDogg(_dot_)net> wrote:
[...]
As Julian mentioned, a SPF record of only "?all" provides no information.
That in mind, does "ipv4:127.0.0.1/24 ?all" really provide useful
information?
Yes, it does. Consider SPF not as a standalone technique but as part of a
larger framework. Then a positive result will allow legitimate mails to
pass the filter framework more easily than a mail with SPF neutral result.
This is similar to using TLS in SMTP, where you can get positive (verified
cert), neutral (no cert or not verifiable) and negative (cert failed
verification) results when checking the sending system's identity.
Rejecting on definite failuers is fine and you can give a bonus for
positively identified systems as their owners are less likely to send spam
since they can be more easily identified and prosecuted.
For simple black/white filtes you are right, in those cases you can only
use the negative results, but in scoring filters (which IMHO are widely
deployed, e.g. procmail and spamassassin) the positive results are useful
too.
Ralf Döblitz
-------
Sender Policy Framework: http://spf.pobox.com/
Archives at http://archives.listbox.com/spf-discuss/current/
To unsubscribe, change your address, or temporarily deactivate your subscription,
please go to http://v2.listbox.com/member/?listname=spf-discuss(_at_)v2(_dot_)listbox(_dot_)com