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Use of the nsZones DNSBLs is free of charge for everybody. You can use nsZones public mirrors free by setting your mail server's DNSBL feature to query bl.nszones.com

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Professional DNSBL

Synchonize option is available for internet ISPs, organizations, networks, hosting providers, email providers.

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DNSBL / RBL Services
(DNS BlackList or DNS Blackhole List or Realtime Blackhole List) A system for identifying spammers based on their IP addresses. Most mail servers are able to query a DNSBL to determine if a specific IP address is on the list.

DNSBL/RBL uses the DNS protocol to query the well-known IP addresses which have been complaint to send worm, virus & junk mail. Using RBLs to prevent junk, virus & worm email is very effective. The algorithm of RBLs is different with that of Anti-Spam and Anti-Virus services as RBLs works based on IP address, while Anti-Spam and Anti-Virus services work based on the message content.

The nsZones (RBL) utilizes a standard DNSBL (Domain Name System Block List) implementation that can be used to reduce spam volume on many popular email systems. DNSBL systems list IP addresses, often those that have been observed by the list operator to be sending spam or hosting spammers. By adding DNSBL entries to an email server configuration, those email servers can either reject connection attempts from listed IP addresses or use that listing to apply appropriate filtering policy.

It is important to note that a DNSBL cannot stop anyone from sending email. A DNSBL only prevents delivery at the receiving end at the receiver's instruction. DNSBLs are strictly defensive tools, and they cannot do any offensive damage such as denial of service attacks.

SURBL is an abbreviation for Uniform Resource Identifier Blacklist. A SURBL lists domain names that appear in URIs such as web sites mentioned in message bodies. This is similar to a DNSBL but it lists domain names rather than IP addresses.

The DNSBL / RBL can be queried directly as bl.nszones.com

Currently, the following zones exist:
  • bl.nszones.com combination of sbl.nszones.com and dyn.nszones.com in a single zone.
  • sbl.nszones.com (Open Relay, Hijacked PCs, Spam Source)
  • dyn.nszones.com (Dynamic, ADSL, Cable, no PTR Networks)
  • ubl.nszones.com (Domain Names, PTR of Dynamic Networks)
Public Mirror DNSBL Servers

We are always need boxes at different locations to help us provide our services.
Anybody can host a nsZones.com public mirror.
You can use your Windows, Linux or Unix dedicated or VPS server.
We will give you access to our databases and you will setup your DNSBL for public use.
We will provide you the software, help and support to setup your DNSBL server.
You do not have to give us any access to your server.
You will manage and setup your server by your own.

If you want to host a public mirror, please contact us to service@nsZones.com.

Please donate to the Project.

nsZones spends a lot of time and money keeping this project running and offers a first class service free of charge to you.

If you are satisfied with our service, and you want the blacklists stay free for all users, we would be glad to receive a small or a big donation from you.

All money donated to the project will be invested in new mirrors and increasing bandwidth so you will also benefit from better performance.

You can donate any amount you want with Paypal.

Smallest amounts can help to keep our blacklists free for all!