The Statistical Spam Filter (SSF) uses naïve Bayes classifiers as a machine learning technique for automatic text classification. This technique can be used to filter out or block spam content.
SSF comes with a submodule that makes use of the service provided by SSF to prevent comment spam (see below).
The service provided by SSF can also be used by other modules to create their own spam prevention functionality.
Stop Forum Spam Client makes use of the www.stopforumspam.com api services for blocking spam, spammers and spambots.
The modules aims at blocking spammers from registering and unregistered users from spamming.
Features
Prevents known spammers from registering as user
Detects and disables registered users that are known spammers
Blocks known spammers from posting content
Blocks known spammers from posting comments
Blocks known spammers from sending contact mail
Maintainer can report individual content and comments as spam
Maintainer can report individual accounts and contributions by those accounts
Whitelisting of usernames, e-mail addresses and IP addresses