From Seo Wiki - Search Engine Optimization and Programming Languages
| This article needs additional citations for verification.
Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (September 2008) </td>
How it works
The software is able to send 500,000 e-mail messages per hour from a regular cable modem connection. It affords near-total anonymity because of the networking and is often used by spammers. It currently does have an official website for downloading. But with a price 65$ for the standalone mailer, 80$ with included proxies, and 120 with a bundle of millions of email lists.
Robert Soloway, one of Internet's biggest spammers, used it. On July 23, 2008, the 29-year-old Solway was sentenced to nearly four years in prison and ordered to forfeit more than $708,000 in income. Prosecutors had asked for a 9-year sentence. He has also lost civil suits for spamming, and owes civil penalties totaling more than US $17 million. 
Where It's Sold?
As the project was killed due to controversy it was continued by the original coders partner. There have been a number of "Free" versions floating around the internet of this spam tool. Every "Free" version contains errors and Trojans. The new site is http://www.darkmailer.info where it still thrives, the problem with trying to stop sales of this tool is the tool itself is not illegal. But the user's actions and how he uses it "Can be" illegal.
Cracks and branches
Dark Mailer is the hub of quite a few mass spamming utilities. One of the most prominent is dm.cgi, a script which bombards predefined e-mail addresses using the CGI capabilities of compromised websites or whole servers.