This paper outlines and exemplifies a spam (unsolicited commercial and other undesirable email) foiling system developed by the author. This automatic email filtering system is based on the concepts of whitelisting and blacklisting as adopted by the author in 1994. The paper suggests the idea of email password requirement returned automatically to the sender before accepting email as adopted by the author in 1997 for his own email protection. The paper also contributes the author's own method for testing the filtering recipes for procmail autonomous mail processor, and in an appendix a WWW-page based variant of the main password method.
"Looks like Timo had the right idea years ago!" (Berkes 2003). "For me, the day I read Professor Timo Salmi's webpage was a good day." (Clifford 2003).
Timo Salmi, Professor, Department of Accounting and Finance, University of Vaasa, P.O. Box 700, FIN-65101 Vaasa, Finland, e-mail ts(a)uwasa.fi, http://www.uwasa.fi/~ts/.