Anatomy of a mail rule Each mail rule takes the same basic form: •       the header to perform a test on •       the test to perform •       the action to take if the test is successful. Note A colon (:) always separates the header from the test Here is an example of a simple mail rule: X-Mailer: "Millennium Mailer" SET $spamlevel +=75 where •       X-Mailer is the header on which to execute the rule •       the test to perform is, whether the X-Mailer header contains the data Millennium Mailer •       the action to perform, in this case, is to add 75 to the $spamlevel variable Top