Mad Mimi is an email marketing service created in 2008 by Leah and Gary to promote their music company. As they could not find an email service that met their needs, they decided to design their own. Mad Mimi makes it easy to build an email list and create an opt-in page where users can provide their email to sign up for updates. The document provides step-by-step instructions for setting up an opt-in page using Mad Mimi, including creating an account, designing the opt-in form, embedding the form on a website, and viewing the live opt-in page.