Spamdyke is a filter for monitoring and intercepting SMTP connections between a remote host and a qmail server. Spam is blocked while the remote server (spammer) is still connected; no additional processing or storage is needed.
In addition to all of its anti-spam filters, spamdyke also includes a number of features to enhance qmail.
For more info about Spamdyke visit http://www.spamdyke.org/.
Every time an email is blocked, spamdyke also provides an explanation in the form of return code. This error code has its own description that I wanted to make it easily accessible to all users of WordPress.
To run the plugin Spamdyke Analyzer is necessary to enter in the configuration file of the spamdyke, spamdyke.conf, the following line (suitably modified) with your address, for example: policy-url = http://www.alessandroconsorti.it/spamdyke?code=
For more information go to this page link