+++++++++++ STOCKADE - A network-level spam mitigation tool ++++++++++++

Name: Stockade

Version: 0.2

Release date: 16 March 2007

Overview:

 Stockade is a TCP-layer tool for reducing the level of network
 traffic arriving at an SMTP server due to spammers.

 The Stockade blacklist server (blserv) operates at the network
 level as a filter. It sits 'in front' of your mailserver, rejecting
 incoming TCP connections from known (or suspected) spammers. The
 rejection is statistical in nature, based on the presumed likelyhood
 of a new connection's source being 'a spammer'.

 Stockade is designed to collaborate with existing spam classification
 tools, such as SpamAssassin or SpamBayes.  A set of tools are provided
 that enable external applications to register spam with the blacklist
 server, using a simple text-based protocol.  See doc/protocol.txt for
 details.

 A unique feature of stockade is the auto-rehabilitation of IP
 addresses that have previously been declared to be spammers.
 Blacklisted IP addresses initially have new TCP connection attempts
 rejected with 100% probability. Then, over time, stockade slowly
 rehabilitates the IP address - reducing the connection rejection
 probability a few percent at a time. If the source sends new spam
 in the future, the rejection probability goes back to 100%. Otherwise,
 the source is eventually rehabilitated (allowed to resume sending
 us emails) without manual operator intervention. A number of configuration
 options exist for mail server managers to adjust the rehabilitation process.

 The stockade distribution consists of:
   - blserv: a local blacklist server
   - Three methods of accessing the server for spam registration:
       - register_spam: A command line executable
       - Stockade.pm: a Perl module
       - libstockade.a: A C++ library
   - load_test: A load / stress testing suite

 See the INSTALL file for installation instructions.

Copyright and authorship:

 Stockade is copyright (c) 2007 Swinburne University of Technology,
 Melbourne, Australia (CRICOS number 00111D).

 Stockade was developed by Malcolm Robb (mrobb@swin.edu.au) while a
 research assistant at the Centre for Advanced Internet Architectures
 (http://caia.swin.edu.au), December 2006 to March 2007.

Licensing:

 Stockade is released under the GNU General Public License version 2
 (see the file COPYING for details).

Acknowledgements:

 This work was supported by a grant from the auDA Foundation
 in October 2006. The auDA Foundation a charitable trust established
 by .au Domain Administration Limited (auDA) to promote and
 encourage education and research activities that will enhance
 the utility of the Internet for the benefit of the Australian
 community. More information may be found at:
 http://www.auda.org.au/news-archive/auda-05102006/

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