Spam Blacklists
A spam blacklist is a specialized database containing the Internet addresses (IP’s) of identified spammers, that is a company or persons who generate spam. Internet Service Providers (ISPs) as well providers of bandwidth can subscribe to these databases to assist them in filtering spam from their network and their subscriber services. If you are no webmaster on your own you will most probably not have to think of these systems, your providers will take care of the matter.
Multiple blacklist organizations are in place for the purpose of identifying those networks that support and contribute to spam through various methods such as, distribution of spam software and programs, open relay hosting, hosting websites, and other means. Network mail servers can be configured to reference these lists automatically for identifying suspected spam addresses.
By identifying a DNS configuration from the sender, and comparing it to DNS configurations in the blacklist database, the mail server can confirm if the address originates from a spamming person or company. If it confirms the address as a spammer, an error message is invoked, and the email is refused. In this way, the spam is not delivered to the mail server subscribers. To effect more drastic punishment, some blacklist organizations may distribute Internet routing information that causes all email from the identified spam IP to be discarded or refused, effectively creating an Internet “black hole” that is unreachable from your network.
Blacklist Organizations
The widespread and rampant intrusion of spam on the Internet has resulted in several blacklist organizations being developed to provide blacklist databases for ISP’s and bandwidth providers. All of these organizations can offer ISP’s or bandwidth providers with the tools to eliminate and reduce spam on their networks. Some of the highly recognized organizations include:
The Top Blacklist Organizations
Spamcop, MAPS, and SpamHaus have been recognized as three of the top blacklist organizations for their stringent attention to maintaining current and valid blacklists and white lists (lists designating IP’s as valid and non-spamming), as well as efficient programs offered to ISP’s and network providers to assist them in the battle against spam.
Stopping Spam
Unfortunately, spammers persist despite the aggressive and efficient efforts of blacklist organizations. Due to the fluctuating nature of the Internet, spammers find ways around the roadblocks. However, one certainty remains, blacklist organizations have made it extremely difficult for spammers and force them to work through many twists and turns to continue their trade. Whether an ISP, or an end-user on a personal computer, blacklist organizations have developed the tools to reduce and in some cases eliminate spam. For ISPs, spam is reduced at the mail server by use of these tools, for the end-user, reporting spammers to blacklist organizations initiates the step to take them out of service.