The Spam Settings page allows you to configure how Movable Type handles undesirable comments and TrackBack pings.
Auto-Delete Spam: When checked, Movable Type will automatically delete comments and TrackBacks designated as spam, after the period of time specified in the “Delete Spam After” option described below.
Delete Spam After: This option specifies the number of days that Movable Type will wait before auto-deleting spam. This option is only available if “Auto-Delete Spam” is checked.
Spam Score Threshold: This control provides a junk tolerance level for all comments and TrackBack pings received on a blog. The value of this setting will be considered the baseline for “non-junk” for all future feedback to the blog and any with a “Final feedback rating” lower than the threshold will be considered “junk”. This setting provides an administrator to lessen the impact of “noisy” yet effective anti-spam plugins. Threshold values can be any real number between -10 and 10 and can be adjusted via the slider although Six Apart strongly recommends the default value of “0.”