< Previous Page Return to Title Page Next Page >

DNS Blacklists

  • Help server to reject connections from likely spammers
  • DNS used to query database
  • MAPS (mail-abuse.org)
    • RBL: Known, recalcitrant spammers
    • DUL: Dial-up lines
    • RSS: Open relays with history of spam relaying
    • RBL+: Combined database for fast lookups
    • Charge for all but individual use as of 7/31/2001
  • ORBS (defunct as of 3Q 2001)
    • A blacklist with "attitude." Blocked any server that refused to be probed for relaying
    • Since the demise of ORBS, several similar, mostly free blacklists have been created. (See paper)
  • Sendmail macros for common blacklists:
  • FEATURE(dnsbl,`blackholes.mail-abuse.org',`RBLed! see http://www.mail-abuse.org/rbl/')dnl
    FEATURE(dnsbl,`dialups.mail-abuse.org',`Dialup! see http://www.mail-abuse.org/dul/')dnl
    FEATURE(dnsbl,`relays.mail-abuse.org',`Open relay! See http://www.mail-abuse.org/rss/')dnl
    FEATURE(dnsbl,`inputs.ordb.org',`Open relay! See http://www.ordb.org/')dnl