Extension:Check Spambots/check spammers plain.php

This code is from it-mate.co.uk but has had the following bugfixes applied:
 * Addresses of all DNS blacklists must be specified with trailing dots (ie: "example.org." not "example.org") as PHP may otherwise handle a "not found" (NXDOMAIN) condition by returning the server's own address - a false positive
 * Addresses of individual files (code or configuration) included from within the scripts must be changed to specify proper pathnames instead of using "./" (the path to the current directory).

See Extension:Check Spambots for full installation instructions.