Binary package “bld” in ubuntu precise

Black List Daemon, automatically build blacklists

 BLD stands for "black list daemon" and is intended to build blacklists
 using simple rules based on a maximum number of submissions of the same
 IP address during a minimum time interval. BLD was primarily designed to
 fight against dictionary-based spams (by making the MTA report to BLD
 any host that tries to send a mail to an unknown user) but can be used
 by any application that needs a blacklist based on connection rate
 This package contains the server.