Real protection requires server side code, which means an ISP that allows CGI, ASP, etc. Since there are several different server side languages, rather than give comprehensive solutions in this FAQ, some URLs which offer solutions/assistance are included.

www.turnstep.com/Spambot/cgi.html gives details and C source and Perl scripts for implementing a CGI solution which outputs the mailto tag to the browser.

An alternative method is to use code to actively look for and deny access to the spambots. For example check the referrer and if recognised (either by IP or by agent type) take appropriate action. This requires a list of known reprobates however and will not protect from new spam-bots just starting up.

www.ahref.com/guides/technology/200009/0922piou.html is Apache and PHP vs. the Spambots. Claimed to be pretty easily adapted for Perl instead of PHP.

www.turnstep.com/Spambot/detection.html Spambot Beware. Detection of Spambots. Explains how to detect spambots using CGI and your raw access logs.

www.spamhaus.org/sbl/howtouse.html Spamhaus maintain a block list that can be used with server side solutions.