I had wondered whether this should be integrated into SPF as well. A
single statement in section 2.2.2:
If the DNS lookup returns NXDOMAIN, then the SPF processing must abort
and return "fail".
Note that this is not as strong as saying that a domain must be able (in
theory) to handle mail. It is a cheaper operation as well, since only
the return code needs to be checked.
Philip
Marc Alaia wrote:
Is there a way to differentiate between a domain not having a TXT record and
not existing at all?
For example, if an email comes in that is from user(_at_)example(_dot_)com, but
example.com does not exist or does not make sense (I just got 5 messages
from "UEXSVBPD(_at_)eager farmington current paper controversy nostradamus
eastern demon aug mckenna berra shipmate thunderstorm microbial credential
counterfeit trapezoidal coerce" as reported by my SPF Proxy log). To me,
this is about the same as an explicit SPF Fail. If the domain is not
registered, then the email cannot come from that domain!
Since SPF does not address this scenario (right?), couldn't spammers just
use non-existant domains?
Marc
-------
Sender Permitted From: http://spf.pobox.com/
Archives at http://archives.listbox.com/spf-discuss/current/
Latest draft at http://spf.pobox.com/draft-mengwong-spf-02.9.5.txt
Wiki: http://spfwiki.infinitepenguins.net/pmwiki.php/SenderPermittedFrom/
To unsubscribe, change your address, or temporarily deactivate your subscription,
please go to http://v2.listbox.com/member/?listname(_at_)©#«Mo\¯HÝÜîU;±¤Ö¤Íµø?¡
-------
Sender Permitted From: http://spf.pobox.com/
Archives at http://archives.listbox.com/spf-discuss/current/
Latest draft at http://spf.pobox.com/draft-mengwong-spf-02.9.5.txt
Wiki: http://spfwiki.infinitepenguins.net/pmwiki.php/SenderPermittedFrom/
To unsubscribe, change your address, or temporarily deactivate your subscription,
please go to http://v2.listbox.com/member/?listname(_at_)©#«Mo\¯HÝÜîU;±¤Ö¤Íµø?¡