> What I am targeting will not be on an abusive domains on any RBL > anywhere as they buy these domains for the sole purpose of targeting our > company and our clients. They only have to succeed once where I have to > succeed every time to keep them from stealing large sums.
What about the ip ranges? I have the impression that once you register these, it gets less. There are specific providers offering their networks for such services. Legitimate providers do not want to get involved with such networks, because they will end up on blacklists. I am having a combination of ip ranges that I have registered, these get from me an url in a confirmation, only when this url is clicked the email is accepted. You could tune this for your environment. Maybe you can do something with the connection country [@]# dig +short -t txt 95.80.124.107.origin.asn.cymru.com "7018 | 107.64.0.0/10 | US | arin | 2011-02-04"
