Repeated Blacklisting / IP reputation

Jon Lewis jlewis at
Tue Sep 8 19:08:38 UTC 2009

On Tue, 8 Sep 2009, Wayne E. Bouchard wrote:

> This is not actually a new problem. ISPs have been fighting this for
> some time. When a dud customer spams from a given IP range and gets it
> placed in various RBLs, when that customer is booted or otherwise
> removed, that block will probably get reissued. The new customer then
> calls up and says, "my email isn't getting through." All it takes is a

The difference/issue here is that it's easy for you when turning down or 
turning up a customer to check the IP space being revoked/assigned in the 
various popular public DNSBLs, sparing your customers the headache of 
being assigned blacklisted IPs.  Until your next customer starts using the 
space and can't send us email, you have no way of knowing that we null 
routed the subnet on our MX cluster.

  Jon Lewis                   |  I route
  Senior Network Engineer     |  therefore you are
  Atlantic Net                |
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