Blacklists Compared

11 August 2001

[ Fighting Spam | Blacklists Compared | Current Blacklist Comparison ]

Survey results for all known public IP-based DNS blacklists.

  Hits   DNS Zone
  5238  (total number of IP addresses tested, including 296 at SDSC)
   905  xbl.selwerd.cx
   793  (union of all zones except xbl.selwerd.cx)
   385  outputs.orbz.org
   234  or.orbl.org
   227  relays.ordb.org
   209  inputs.orbz.org
   162  blackholes.five-ten-sg.com (result 127.0.0.4 = unconfirmed opt-in)
   151  relays.osirusoft.com (result 127.0.0.2 = relay)
   144  relays.mail-abuse.org
    53  dev.null.dk
    51  blackholes.five-ten-sg.com (result 127.0.0.3 = dialup)
    49  spammers.v6net.org
    41  blackholes.five-ten-sg.com (result 127.0.0.2 = spam source)
    36  orbs.dorkslayers.com
    20  dialups.mail-abuse.org
    19  relays.osirusoft.com (result 127.0.0.3 = dialup)
    13  blocktest.relays.osirusoft.com (not a blacklist!)
     9  ztl.dorkslayers.com
     3  orbz.gst-group.co.uk (result 127.0.0.3 = relay)
     3  relays.osirusoft.com (result 127.0.0.6 = spamware vendor)
     3  blackholes.five-ten-sg.com (result 127.0.0.5 = should be listed at MAPS)
     2  blackholes.mail-abuse.org
     2  relays.osirusoft.com (result 127.0.0.4 = spam source)
     1  orbz.gst-group.co.uk (result 127.0.0.2 = relay output)
The web sites listed below provide detailed information about the DNS zones listed above, including their listing policies.

There is no known descriptive page for the list at xbl.selwerd.cx, where the listing policy is so aggressive that even its owner uses a whitelist to keep it from blocking wanted e-mail. Anyone contemplating the use of this zone to automatically block e-mail would be well advised to use a thorough whitelist of their own.
This document was last updated by Jeff Makey <jeff@sdsc.edu> on 12 August 2001.