17. The software of claim 14 , further comprising: a user interface, which is generated by said software executing on the computer system, said user interface being configured to permit a user to determine whether to create said unique variations that are associated with serial numbers created by the serial number generator.
14. Software stored in at least one tangible storage medium and that is able to be loaded, and executed by the computing system comprising hardware to control the computer system, said software for tracking email recipients using modified message content comprising: an original word set comprising a plurality of words included within a body of an email message, which is referred to as an original message, said said original message being digitally encoded in the tangible storage medium communicatively linked to the computer system; a plurality of substitution sets digitally encoded in the tangible storage medium, each associated with one of the plurality of words of the original word set, wherein each of the substitution sets comprises at least one synonym for the associated original word; a serial number generator, which is part of said software that when executed by the computer system is operable to generate a plurality of unique serial numbers that are to be associated with a unique variation of the original message, wherein given a unique serial number and given the original message, the unique email message associated with the unique serial number is able to be automatically generated by an algorithm, wherein a number of statistically unique combinations of original words and associated substantiation sets determines a number of unique serial numbers that the serial number generator is able to generate; and a unique message generator, which is part of said software that when executed by the computer system is operable to receive the original message and a unique serial number as input and to generate a unique variation of the original message as output, wherein each unique variation is an email body for an email message in which two or more of the words from the original word set have been substituted with associated words of the substitution set, wherein the original word set and the substitution sets are specified by digitally encoded data stored in a computer readable media, and wherein serial number generator and the unique message generator are software digitally encoded in a computer readable medium executable by a computing device, which causes the computing device to perform a set of actions for which the serial number generator and the unique message generator are configured.