Settings > Options > Spam Management
Controls the service that is used for scanning supported data. The corresponding API key for the service has to be entered. The current options are Akismet and Typepad Anti-spam.
vBulletin Anti-Spam Key
Enter a vBulletin Anti-Spam service key to enable scanning of user data where supported. You obtain your key from the service selected in the option above. Entering a key, enables this functionality.
Spam Scanning Post Threshold
This setting controls how many of a user's posts will be scanned by the Anti-Spam Service. Once a user's post count exceeds this threshold, his or her posts will not be scanned for spam content. To always scan posts set this value to 0.
Anti-Spam Data Storage Length (Days)
Whenever a post is made, extra anti-spam data is stored. This allows details about false positives and false negatives to be submitted to the chosen anti-spam system to improve it.
This value controls the length of time (in days) for which this data is stored.