From: "Eric Dean" <eric(_at_)purespeed(_dot_)com>
However, what is of value is that we use the C/R as a probe to see if an
actual email address really exists. When a spammer spoofs an aol or yahoo
address..and use a bogus sender..we get an immediate unknown-user reject..as
opposed to other systems that ingest the message and then bounce later
(bounce messages are of a type variety). We actually drop a non-trivial
percentage of spam just by probing the sender's email address.
By this measure, how many of the addreses at free providers are invalid
when you test them?
Depending on how you treat failures to respond to C/R probes, you should
also be able to guage how quickly drop boxes are terminated.
Have you sampled the system to see how many of the messages dropped
are spam instead of legitimate mail with "munged" or otherwise bogus
sender addresses?
Vernon Schryver vjs(_at_)rhyolite(_dot_)com
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