On Fri, 2005-04-01 at 20:19 -0600, Mark A. Lewis wrote:
I have never understood the precived connection between reverse DNS and spam. I have seen some go as far as if the reverse DNS does not match the senders domain they will kick it.
Mostly because a trojaned machine on a broadband connection spewing SPAM will not have a valid reverse DNS entry.
Riight. Ever done a reverse lookup on a RR IP? Rogers? SBC? All of them will have valid reverse entries.
By forcing a policy of accurate reverse DNS, most of the home-broadband- SPAM factories are shut down.
I would argue that using that logic none of them will be shut down.
Not trying to pick any fights here, I just feel very strongly that the logic is very flawed and am looking for some real justification of this.
On Fri, 2005-04-01 at 21:04 -0600, Mark A. Lewis wrote:
Riight. Ever done a reverse lookup on a RR IP? Rogers? SBC? All of them will have valid reverse entries.
See below.
http://searchcio.techtarget.com/sDefinition/0,,sid19_gci917504,00.html
"Reverse DNS (rDNS) is a method of resolving an IP address into a domain name, just as the domain name system (DNS) resolves domain names into associated IP addresses. One of the applications of reverse DNS is as a spam filter. Here's how it works: Typically, a spammer uses an invalid IP address, one that doesn't match the domain name. A reverse DNS lookup program inputs IP addresses of incoming messages to a DNS database. If no valid name is found to match the IP address, the server blocks that message."
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Mark A. Lewis -
ryanag＠zoominternet.net