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What Is SORBS?


SORBS, founded by an Australian named Matthew Sullivan, stands for Spam and Open-Relay Blocking System.

At one point in our Internet's young past, open relays were a huge problem.

An open relay is simply an email server, which allows anybody in the world to connect to, and send email through.

The problem with this is that junk senders could simply search out these open relays and send mass quantities of mail through them with impunity. By the time the administrators knew what hit them, the spammer was long gone and had moved on to the next open relay.

Soon afterwards, the programmers of popular Internet Mail Server software began writing access controls to limit who could relay through their servers.

Now, a decade or so later, virtually all email software being made is set as a closed relay by default, and the administrators must manually specify all hosts who are permitted to use the relay.

In that 10+ year span, SORBS (and others) began compiling lists of IP addresses belonging to servers whose administrators had not secured their relays, and made the lists publically available to other administrators.

Relieved email operators everywhere began utilizing these lists of IP addresses to keep mail out from the open relays.

Over time SORBS expanded its base to include other undesirable email sources, such as dynamic IP ranges, and spamhauses (known sources of mass unsolicited bulk email.)

Today, it continues via the use of spamtraps (unusual email addresses created and posted online in obscured format to gather evidence of spidering, an unscrupulous manner of collecting email contacts) among other things to build its substantial lists.

As of this writing, the SORBS database contains over 3 million IP addresses.

Author: Heather Seitz

Attention Readers, Publishers, Editors, Bloggers, and Marketers: You may republish or syndicate this article without any charge. The only thing I ask is that you keep the newsletters, article, or blog post exactly as it was written and formatted, with no changes. You must also include full publication attribution and back links as indicated.

This information has been provided by http://www.EmailDelivered.com and written by Heather Seitz. To find out more about SORBS, visit http://www.emaildelivered.com/email-delivered/what-is-sorbs/. Don’t forget to sign up for the EmailDelivered Pulse newsletter for articles, tips, and recommended resources related to email marketing and email deliverability.

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