dialin-spammer-block can be used to detect and block dialin clients
that try to send spam over your mailserver.
A spammer is detected by watching the mailserver logfile and counting
the mails sent by each dialin client. If a client exceeds the limit
of mails that may be sent during a certain amount of time, the client
will be blocked to relay further mails on your mailserver until the
RADIUS server reports that the client has disconnected.
A good thing is to use it together with port 25 redirection for dialin customers: www.init7.net/anti-spam.
dialin-spammer-block is free software (GPL).
Copyright (C) 2002, Marco
Steinacher, Init Seven AG