15. A computer system for identifying undesirable electronic messages, the computer system comprising: means for identifying incoming electronic messages; means for normalizing identified electronic messages according to a plurality of rules for distinguishing non-legitimate words from legitimate words, said normalizing further comprising identifying non-legitimate words obfuscating electronic messages according to the plurality of rules, and deleting the identified non-legitimate words from the electronic messages; wherein said plurality of rules for distinguishing non-legitimate words from legitimate words comprises at least three rules from a group of rules consisting of: a rule specifying a maximum number of consecutive vowels in a legitimate word; a rule specifying a maximum number of consecutive consonants in a legitimate word; a rule specifying a maximum number of consecutive uses of any single character in a legitimate word; a rule specifying a maximum number of transitions between upper case letters and lower case letters in a legitimate word; a rule specifying a maximum length of a legitimate word containing numbers without punctuation; a rule specifying a maximum length of a legitimate word containing upper case letters, lower case letters and numbers; a rule specifying a maximum length of a legitimate word containing upper case letters, lower case letters, numbers and punctuation; a rule specifying a minimum number of vowels in a legitimate word; a rule specifying a minimum number of consonants in a legitimate word; a rule specifying a minimum ratio of vowels to consonants in a legitimate word; and a rule specifying a maximum ratio of vowels to consonants in a legitimate word; and means for analyzing normalized electronic message to identify undesirable electronic messages.
18. The computer system of claim 15 wherein the means for analyzing normalized electronic message to identify undesirable electronic messages further comprises: means for keeping a count of detected items to be normalized in an electronic message; and means for using data concerning a relationship between the count of detected items and a dynamic threshold value as evidence in the identification of an electronic message as undesirable.