9. A method for generating a set of email messages, each containing approximately the same content that has been slightly varied so that each generated email message is unique, said method comprising: identifying an email message containing textual content of a body of the email message; determining a set of at least two recipients who are to receive a unique variation of the identified email message; detecting a set of at least two words contained within the textual content of the body of the email message, wherein each of the words of the set have at least one synonym; for each detected word, assigning at least one replacement word, wherein each of the replacement words is a synonym of the corresponding one of the words of the set; generating a set of unique email messages, one associated with each recipient in the determined set of recipients, wherein each unique email message has a unique combination of detected word substitutions in a body of the corresponding email message; for each generated email message, calculating a unique serial number based upon which replacement words are included in the body of the associated email message, wherein given a unique serial number and a formula used in the calculating step and given the textual content, the unique email message associated with the unique number is able to be automatically generated; sending said unique email messages to associated recipients; and storing the unique serial number and an identifier for the associated recipient.
12. The method of claim 9 , is manually selected by a user of a user interface from a set of presented possible word replacements.