Fighting Spam

[ Fighting Spam | Dialup Zones | Blacklists Compared | Current Blacklist Comparison | Sendmail Configuration ]

These pages document some of my efforts to fight unsolicited bulk e-mail, or "spam" as it is commonly called. One technique that is very effective for blocking spam is to maintain one or more blacklists of spam sources, and then refuse all e-mail from those sources. The hard part is choosing the best blacklist(s), because different blacklists have different listing policies, and the more aggressive ones often list sources that send legitimate e-mail as well as spam. Other lists are so conservative that they block almost nothing at all. To aid in the selection of one or more of the public DNS-based blacklists I publish a comparison report that summarizes my weekly survey results.

I maintain my own list of dialup zones, but it is not available as a DNS-based blacklist.

See how I have modified Sendmail to block a large fraction of the spam that is sent to SDSC.

This document was last updated by Jeff Makey <> on 14 August 2012.