When the Normalize Words option is selected, all words in a message are normalized before they are added or compared to the phrase list or antispam-table.txt file. Normalizing consists of stripping out all non-alphabetic characters (any character other than A-Z, a-z).
Example:
F1rst becomes frst
s*e*x*y becomes sexy
Note: If a word containing a number or non-alphabetic character is frequently used in your mail messages, such as a company name, we recommended that you do not enable the Normalize Words option.