--On Tuesday, 10 May, 2005 12:35 -0700 Kartik Gopalan
<kartik(_dot_)gopalan(_at_)gmail(_dot_)com> wrote:
Thanks for your note. In DMTP, we use coarser MTA classifiers
at the level of their IP address or domain names -- not the
fine-grained email-address classifiers (as you seem to mention
below). Using the latter would indeed have the problems you
describe -- but DMTP I-D does not use email-address
classifiers. Its possible to do that, but only with the kind
of strong sender authentication you mention, which is the
reason we steered away from them in the first place.
Unless you abandon mail relaying, and perhaps even if you do,
domain names and IP addresses are as easily spoofed as full
email addresses. The spammers figured both out many years ago.
john