Free spam IP blocker according to public DNSBL bases.
Now plugin uses just one default DNSBL checker. DNSBL class also fixed to aviod this problem: [http://www.spamhaus.org/faq/answers.lasso?section=DNSBL%20Usage#243 "Your DNSBL blocks the whole Internet!"]
Added the new feature of new DNSBL class version. Group checking is back, 'all' key provides checking in group available checkers, now they are 'spamhaus' & 'spamcop'. See readme of DNSBL class for details: [http://www.phpclasses.org/package/6994-PHP-Check-spam-IP-address-in-DNS-black-lists.html "DNSBL class on PHPClasses.org"]