This section provides information about configuring comment settings and administering the comments queue in Drupal 7.
Modules to reduce spam comments:
- Mollom is configurable to offer both text analysis as well as CAPTCHA
- CAPTCHA is a module that makes it easy to embed CAPTCHAs to prevent spam. The module page is a great reference guide to many other CAPTCHA like modules and other spam fighting modules
- Honeypot and Botcha also are effective solutions. The project pages of these modules contain references to even more spam-protection modules.