mail abuse prevention system (MAPS)
The MAPS organization fights spam mails. It registers all Internet computers from which spam is sent.
Mail Abuse Prevention System (MAPS) creates several lists, including the Realtime Blackhole List ( RBL), the Dynamic User List (DUL), the Non-confirming Mailing List( NML), the Open Proxy Stopper ( OPX) and the Real Spam Stopper( RSS). The various lists are made available to providers and users in return for a user fee. Providers can use this list to carry out appropriate filtering and thus protect their customers' e-mail traffic.