SURBL

SURBL (previously stood for Spam URI RBL) is a collection of URI DNSBL lists of Uniform Resource Identifier (URI) hosts, typically web site domains, that appear in unsolicited messages. SURBL can be used to search incoming e-mail message bodies for spam payload links to help evaluate whether the messages are unsolicited. For example, if http://www.example.com is listed, then e-mail messages with a message body containing this URI may be classified as unsolicited. URI DNSBLs differ from prior DNSBLs, which commonly list mail sending IP addresses. SURBL is a specific instance of the general URI DNSBL list type.

Lists

SURBL provides several different lists from different sources:

All lists are gathered into multi.surbl.org.

Usage

A DNS query of a domain or IP address taken from a URI can be sent in the form of spamdomain.example.multi.surbl.org or 4.3.2.1.multi.surbl.org. The multi DNS zone return records contain codes that indicate which list contains the queried for domain or IP address. Many spam filters support use of SURBL. Small sites can use SURBL through public DNS queries, and an rsync data feed is available to professional users. SURBL data are also available in Response Policy Zone and CSV formats.