Implement DNSBL checks (3)

Result (from /var/log/exim/mainlog)
2003-12-28 08:00:05 H=cnq11-245.cablevision.qc.ca (shiraume.ac.jp) [24.212.11.245] F=<glenda_k_mobley_yo@online.se> rejected RCPT <smtpsurvey@liquidzero.net>: Blocked - see http://cbl.abuseat.org/lookup.cgi?ip=24.212.11.245

Testing
   run a fake SMTP session as if from the given IP
   exim -bh  <IP address>