Spam is one of the biggest problems on the Internet. The "data garbage" spreads mainly via e-mail and has many unpleasant consequences. Unsolicited e-mails are received by private individuals as well as companies on a daily basis. The large mass of data garbage that is sent via the Internet entails high costs and a large amount of time. The Spam House.org published on its website enormous amount of information about spam senders and operates a freely accessible RBL server. IP addresses and domain names of known spammers can be blocked via various blacklists.
Types and effects of spam
Unsolicited mass e-mails are one of the typical types of spam. The messages are sent to a very large number of recipients. Usually these are e-mail marketing campaigns and other advertising related purposes. Commercial e-mails are also sent in large quantities over the Internet. The contents of these e-mails include offers for casinos, sexual enhancers, financial services and software. Other types include collateral spam, backscatter and Usenet spam. Spam or junk causes considerable damage in terms of international communication. The biggest problems are the additional data volumes and the time required to get rid of spam. Reading and sorting out unsolicited e-mail takes a lot of time. In most companies, the Internet is not billed according to time of use, but according to the amount of data. A large amount of spam increases the amount of data and thus the monthly costs of the company increase. A large amount of spam increases the processing time of normal mails and this in turn has a negative effect on productivity. In the USA alone, unsolicited email causes over $22 billion in annual damage. For these reasons there are many companies and organizations that take action against spam and maintain black and grey lists. Spamhaus.org is one of the best known providers who operates a publicly accessible RBL server. A Real-time Blackhole List is a black list that can be queried in real time and through which spam emails can be classified.
What is Spamhaus.org?
The Spamhaus is an international non-profit organization and was founded in 1998. The head office is located in Geneva. The organization has set itself the task of tracking spam activities on the Internet and their originators. In the "Records Of Known Spam Operations" Spamhaus publishes many important details about the spammers. They even mention the names of the spammers and even publish some photos. This information comes from many different sources and most of it is publicly available. The information is only published if there are at least 2 sources as evidence. Based on this information, other users can decide whether you classify a certain email as spam. Spamhaus operates several DNS-based blackhole lists and real-time blackhole lists. It has one of the largest DNS infrastructures in the world. Spamhaus' network consists of more than 80 public DNSBL servers located in 18 different countries. Spamhaus' servers are mainly used by Internet email providers, companies, governments and military networks. Spamhaus offers this whole service without any costs or fees.
The blacklists of Spamhaus in the overview
The mail accounts of around 2 trillion Internet users are protected by the DNSBL lists of the Spamhaus organisation. The company employs independent investigators around the world. The various blacklists of Spamhaus can be used free of charge for non-commercial purposes. Up to 100,000 emails per day is the maximum limit. Spamhaus provides more than 50 public servers for this purpose. If you exceed this volume or use the lists commercially, you have to license the use at Spamhaus.
Spamhaus operates several blacklists
The Spamhaus Block List (SBL) contains numerous IP addresses from which the organization believes that you should not receive email for your own safety. The basis for the entries are various spam events and these are analyzed by Spamhaus and then entered into the database. The Exploits Block List (XBL) contains the addresses of hacked desktop PCs and servers that belong to a botnet. Spamhaus receives the XBL data from the open proxy entries of njabl.org and from the lists of cbl.abuseat.org.
The Policy Block List (PBL) lists IP addresses that have been classified by the major Internet Service Providers (ISPs) as so-called dialup areas. Many experts are of the opinion that mails should not be sent directly from such addresses. Spamhaus itself does not specify the IP addresses that are on the Policy Block List. This is done exclusively by the service providers themselves. The ZEN list (zen.spamhaus.org) is a data combination of the 3 lists XLB, SBL and PBL. If you want to query all 3 lists anyway, you can query the ZEN list directly and save time.
The DROP list (Don't Route Or Peer) contains officially registered IP networks of taken over or insolvent companies which are currently not used. Via the BGP routes, these IP addresses can be hijacked and misused for other purposes, such as spam or cyber attacks. Addresses that are in the drop.spamhaus.org should be blocked in any case. The Domain Block List (DBL) does not contain addresses, as the name suggests, but domains. Only domains that are used for phishing purposes or that are advertised in spam emails are listed.
How to unsubscribe from a Spamhaus blacklist
If your IP address or the address of your provider is on a blacklist of spamhaus.org, your e-mails will be rejected. In this case you can either contact your provider or Spamhaus directly. Via the website of Spamhaus you can manually remove IP addresses and domains from the blacklists.
Visit the official website of Spamhaus. Click the link "Blocklist Removal Center"and you will be taken to a new page. With the "IP Address Lookup Tool" you can check if your IP address is blocked by Spamhaus. Simply enter your address and click on "Lookup". The "Domain Lookup Tool" checks if a website is on the Spamhaus blocklist. Enter the address of your domain and click on "Lookup". Within a few seconds you will see which addresses are blocked. Under each red entry there is a link and you have to click on it. Subsequently, another page will open and on this page you will see detailed information about the responsible blacklist. On this page you will also find a "Remove Button" and click on it. On the next page, you will find the detailed information on what exactly happens when you remove the IP address from the blacklist. Read this information carefully and then check the box. Then click on the "Remove IP Address" button.
A window will open with a form and you must fill it in completely. Enter your IP address and your e-mail address and select your country. Additionally you have to choose if you have a dynamic or static IP address and if you have a personal computer or a server. In the last step you have to enter the displayed code into the form and click on the button "Submit". Your request must also be verified. For this purpose you will receive an e-mail from Spamhaus with a 5-digit code. Enter this code into the form and click on the button "Finish". Your IP address will now no longer be blocked by Spamhaus. To remove a domain address from Spamhaus you can use almost the same procedure.
In most cases, Spamhaus only provides a reference to the CBL Blacklist. Here you will usually get helpful information why your IP address was blacklisted.
You should get this information before you be sure to write down and then analyze how this happened. In some cases, a domain name and a URL is specified via which the spam was sent.
Spamhaus and CBL are currently among the most sensible anti-spam solutions, because the providers provide the providers with helpful information with which the spam dispatch can be analyzed and corrected immediately. The delivery is also very well organized within a few minutes.
How to avoid blacklisting?
A blacklisting of server IP addresses occurs in most cases by sending spam through misused login data or hacked websites. Often, users do not even notice that someone else is sending spam via their own domain.
But there are workarounds to stop getting blacklisted.
Modern web hosting companies like in our example the webhoster.com AG also check outgoing emails from the server for spam, viruses and malware. An email that is sent via a server with a registered domain, for example, does not arrive directly at the recipient, but is first routed via a so-called spam protection gateway, which checks the email and then forwards it to the recipient.
If a mailbox is abused or spam is sent via the website, the gateway will not forward the email to the recipient, but will restrict the mail sending and inform the domain owner.
A Spam protection gateway ensures that almost only valid clean emails are sent to the recipients and that spam is not allowed at all. As a result, the IP addresses of the gateway have a very high reputation and e-mails usually do not end up in the spam folder of the recipient.
In this example, the service is included free of charge in all tariffs. The following is used Spame Experts Gateway, which normally costs about 5 euros per month and domain. The advantage of webhoster.de AG is the local evaluation in their own data center in Frankfurt am Main. As a Spamexperts partner, the provider operates its own cloud with many email gateways. The eMails are therefore not first sent to a Cloud Provider The data is not forwarded abroad, but evaluated in the same data centre where the website is located, in accordance with data protection regulations.
With such a solution you will no longer be blacklisted and your mails will arrive safely at the recipient. A worthwhile investment and perhaps also a reason to change, if you are currently overwhelmed with the management of your domain, or the server.
Link to product: Web hosting with spam protection gateway
Link to instructions: Spam protection gateway on Youtube