Install bogofilter-bdb by entering the following commands in the terminal:
sudo apt update sudo apt install bogofilter-bdb
fast Bayesian spam filter (Berkeley DB)
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. . This package provides the bdb database backend.