From: barmar@alum.mit.edu   
      
   In article ,   
    vjs@calcite.rhyolite.com (Vernon Schryver) wrote:   
      
   > In article ,   
   > Barry Margolin   wrote:   
   >   
   > >> >Sometimes companies put useless A records on their domain name as an   
   > >> >anti-spam measure.  I think there are some spambots that send to the A   
   > >> >record rather than the MX record, so putting 0.0.0.0 or 127.0.0.1 in the   
   > >> >A record will prevent them from sending to you.   
   > >>   
   > >> It will also trigger spam defenses in many SMTP servers (mail   
   > >> receivers) to refuse mail from domain names that resolve to bogus   
   > >> IP addresses.  Domains that can't receive a bounce (NDR) shouldn't   
   > >> be sending any mail.  (Never mind that bounces must be avoided today   
   > >> to minimize spam backscatter.)   
   > >   
   > >But if the name has an MX record then it CAN receive a bounce.  The   
   > >bogus A record is irrelevant, since MX records take precedence.   
   >   
   > That's right; I was thinking of bogus A RRs when the MX does not exist.   
   >   
   > On the other hand, an organization that thinks that a bogus A record   
   > with a valid MX is a start on a FUSSP is unclear on fundamental concepts.   
   >   
   > A modest fundamental concept is that not answering port 25 is as   
   > effective as a bogus IP address but need not risk, as in this case,   
   > losing profitable web page hits.   
   >   
   > More important is that contrary to the regularly shouted delusions of   
   > grandeur of some spammer fighters, spammers have in general always   
   > understood more about email, TCP/IP, and the Internet in general than   
   > too many SMTP server operators and most loud spammer fighters.   
   > (for values of "always" starting at least with Spamford Wallace.)   
      
   I'm just going by what I read.  Maybe it was a year or two ago, someone   
   posted (maybe it was on NANOG, I'm not sure) that when they put a bogus   
   A record on their domain their incoming spam dropped significantly.  I   
   agree that it's ridiculous, I can't imagine spammers falling for such a   
   simple trick, but that's what he said.   
      
   --   
   Barry Margolin, barmar@alum.mit.edu   
   Arlington, MA   
   *** PLEASE don't copy me on replies, I'll read them in the group ***   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)