The Spam and Open Relay Blocking System

Status: Active
Website: www.sorbs.net
Removal: www.sorbs.net/overview.shtml

The SORBS (Spam and Open Relay Blocking System) provides free access to its DNS-based Block List (DNSBL) to effectively block email from more than 12 million host servers known to disseminate spam, phishing attacks and other forms of malicious email. The list typically includes email servers suspected of sending or relaying spam, servers that have been hacked and hijacked, and those with Trojan infestations. In an attempt to provide preemptive protection, SORBS also lists servers with dynamically allocated IP addresses. SORBS maintains 17 distinct DNSBL zones.

Listing Policy

Any server that allows unauthenticated email to be sent through its systems will be listed in the smtp.dnsbl.sorbs.net blacklist. This usually happens by someone reporting the server as an open relay, or by the SORBS scanners and systems noticing that the system allows the sending of email without authentication.