Within Email Editor Rules, the same source can use any number of different templates. Jim2 will then randomly pick a template when sending. For instance, use this to randomly cycle through a number of templates that can advertise various offerings of the business.
First, create the templates to be used for the random templates.
On the ribbon, go to Email > Editor Rules.
Enter the information according to Editor Rules.
As sources and templates are added, hover over the Template field and a pop-up will advise that this template will be chosen randomly from amongst duplicate source rules as in the Templates by Report section.