Added comments

Just embedded some comments into the code.  A general observation: the code you implemented has some very sophisticated behaviors!  However, there are many parts of the code where you are performing the same generic operation repeatedly.  Some examples:

 * Prompting the user for Yes / No input
 * Providing the user w/ an opportunity to add additional emails

The rule I try to follow: if I find that my code is doing the same thing twice, then I should try to move that logic into a method.