Ted Hardie wrote:
Front matter: I'm posting this as just-another-bozo-on-this-bus, not
as this group's Area Advisor.
I didn't know that bozos are so knowledgable :)
So my question one: is it valuable for a domain to be able to list the set
of hosts it "employs" as outbound MTAs?
Yes, this protects the domain from certain types of forgeries (bounces
and phishing). HOWEVER, it does not protect against other types of spam
since spammers can set up their own domains. It does however allow for
an identity that can be used to build other reputation systems.
Also, this notion of outbound checking is present in XMPP is a different
fashion - the servers that connect check each other, however since XMPP
has no notion of "outbound" or "inbound" this is done differently.
My question two: is it valuable for a domain to be able to list the set of
hosts it is "responsible for" as outbound MTAs?
Yes and no. In theory this gives another hoop for spammers to jump
through and allows another vector of identity (WHOIS info) for the MTA.
In practice, without a reputation system it is useless.
Yakov
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Yakov Shafranovich / asrg <at> shaftek.org
SolidMatrix Technologies, Inc. / research <at> solidmatrix.com
"Some lies are easier to believe than the truth" (Dune)
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