The wp-spamspan plugin implements strong automatic anti-spam protection for email addresses in content on a Wordpress site.
There are two parts to the wp-spamspan process. First, this plugin locates email addresses in the body of messages, and rewrites them into an obfuscated form for display.
So, if you have a post that contains the text:
This plugin will rewrite it so that it displays as:
chip [at] example [dot] com
Thus, a crawler or bot would only see the obfuscated email address, and only a user at a web browser would see an actual, clickable email link.
The home page for the spamspan.js script is: http://www.spamspan.com/
The installation is simple, and once installed, the anti-spam protection is automatic.