At 5:55 PM -0500 2003/08/29, Steven F Siirila wrote:
Ideally, MTA's would identify themselves as such. For example:
mta5.exchange.microsoft.com TXT
"ID=MTA,ABUSE=abuse(_at_)microsoft(_dot_)com"
(or whatever format makes the most sense)
I suppose the same could be done using just the reversed IP address, e.g.:
3.2.1.10 TXT
"ID=MTA,ABUSE=abuse(_at_)microsoft(_dot_)com"
I think we can take the previous example of WKS records, and the
current example of PTR records, as predictors of accuracy and success
of this concept. In short, I don't see where this is going to work.
If you're a spammer, and you own your own domain (as so many do),
you can create your own DNS records, so that you can by-pass checks
like this. Indeed, many spammers register domains, spam from them
for hours or maybe a few days, and then throw them away. You'd be
causing legitimate senders to jump through additional hoops to send
you e-mail, but since spammers adapt very quickly, you wouldn't
really be hurting most of them.
If you were using forward records, you wouldn't even slow down
people using viraspam-based distributed spam networks (e.g., those
created by a more sophisticated and less obtrusive version of
SoBig.F), because you could just list wildcard records in the DNS,
and anyone from any IP address could make an apparently valid claim
that they should be allowed to send e-mail through this mechanism.
The situation for reverse DNS is even worse.
I see similar problems for RMX-like proposals.
--
Brad Knowles, <brad(_dot_)knowles(_at_)skynet(_dot_)be>
"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety."
-Benjamin Franklin, Historical Review of Pennsylvania.
GCS/IT d+(-) s:+(++)>: a C++(+++)$ UMBSHI++++$ P+>++ L+ !E-(---) W+++(--) N+
!w--- O- M++ V PS++(+++) PE- Y+(++) PGP>+++ t+(+++) 5++(+++) X++(+++) R+(+++)
tv+(+++) b+(++++) DI+(++++) D+(++) G+(++++) e++>++++ h--- r---(+++)* z(+++)
_______________________________________________
Asrg mailing list
Asrg(_at_)ietf(_dot_)org
https://www1.ietf.org/mailman/listinfo/asrg