A method of processing a plurality of electronic mail files is disclosed, wherein each electronic mail file includes a subject field having one or more strings comprising the steps of establishing a list of strings, checking the first string in the subject field of each electronic mail file to determine whether the first string matches any of the strings in the list, removing any first strings that match a string in the list and replacing the first string elsewhere in the subject field, and sorting the electronic mail files according to their subject field.