The rebuildspamdb.pl script is used to rebuild your Bayesian spam / non-spam database. It reads through all the files in the spam, notspam, errors/spam, and errors/notspam directories and builds the statistical model that is used to test incoming mail. You should use your operating system's scheduling features to schedule it to be run periodically -- possibly daily or at least weekly. The script should be run in the same folder as the assp.cfg file -- your assp's base (from the configuration page).