On Wed, 18 Aug 2004 17:49:22 -0400, smiller@unimin.com
<smiller@unimin.com> wrote:
Our mail administration group recently implemented blocking of all incoming
messages from domains that cannot be resolved via reverseDNS, for purposes
of spam prevention. Of course, there are quite a number of legitimate
business contacts who do not have rDNS properly configured. Assuming that
the rDNS criterion remains, the question becomes one of who will notify
and/or educate the sender(s) about this issue. The only time-efficient way
that I can think of to do this would be to have instructions and references
in the body of the bounce message itself. Anyone tried that? Results?
Other suggestions? Thanks in advance.
Scott
Scott,
I've noticed that AOL has started doing this. Since they've started
I've seen the number of requests for rDNS increment by a huge amount.
In AOL's bounce message they explicitly state that the reason it was
bounced was due to no reverse DNS record existing.
However, I'm not sure exactly how this is suppose to stop spam.
Most implementations I've seen just check to see if a reverse DNS
entry exists. You can put anything you want in there. Only the
implementations that check that a reverse DNS record exists and then
checks that the forward resolves to the same IP seem to do any good.
--chip
Just my $.02, your mileage may vary, batteries not included, etc....
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