used in the "from" or "reply-to" e-mail address. Criticisms edit Some end-users and organizations have concerns regarding the concept of dnsbls or the specifics of how they are created and used. End-users assigned to that same shared mailserver may find their emails blocked by receiving mailservers using such a dnsbl. But they are different. The order was a default judgment, as Spamhaus (which is a UK operation) had refused to recognize the court's jurisdiction and did not defend itself. Other addresses in this block may indicate something specific about the listingthat it indicates an open relay, proxy, spammer-owned host, etc. Cartoon Network and 2018 Turner Broadcasting System Europe Limited. It is possible to serve a dnsbl using any general-purpose DNS server software. URI dnsbl edit A URI dnsbl query (and an rhsbl query) is fairly straightforward. How a dnsbl works edit To operate a dnsbl requires three things: a domain to host it under, a nameserver for that domain, and a list of addresses to publish. Uses of dnsbls edit Most message transfer agents (MTA) 17 can be configured to absolutely block or (less commonly) to accept email based on a dnsbl listing.