bogofilter 1.2.2-2ubuntu1 (amd64 binary) in ubuntu natty

 This package implements a fast Bayesian spam filter along the lines suggested
 by Paul Graham in his article "A Plan For Spam".
 .
 This version substantially improves on Paul's proposal by doing smarter
 lexical analysis. In particular, hostnames and IP addresses are retained
 as recognition features rather than broken up. Various kinds of MTA
 cruft such as dates and message-IDs are discarded so as not to bloat
 the word lists.