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defending Internet e-mail from abuse by spammers

MAPS is a service to limit the transport of known-to-be-unwanted mass e-mail based on the address of the sending MTA (Mail Transfer Agent).

MAPS operates with little overhead: other anti-spam systems typically operate "later in the pipeline," by first accepting the e-mail, and then analysing its headers and/or content for a possible rejection. MAPS tries to avoid accepting the spam message to start with. Although more expensive in terms of network and computing resources, accepting the email does allow personalization and content analysis of the spam, which MAPS does not offer.

The four main services offered are the

  • RBL: the Realtime Blackhole List,
  • DUL: the Dial-up User List,
  • RSS: the Relay Spam Stopper, and
  • NML: the Non-conforming Mailing List.

Project MAPS

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