Joomla Contact Form Won't Send Me My Mail

The first time I set up the Contact form that allows visitor to use the online form to send me emails, it worked like a charm. Just filled in the necessary information in the Joomla configuration and everything worked!

A few months later, I decided to change the email address associated with the form. Woe is me. I wasn't receiving any emails sent through the website. The mail server is working fine though because if I selected "Send copy to me" I receive the copy of the test messages.

So what's wrong? Why?

I added users, before it was only me as the admin.

The email address in the contacts is different from the email address where the form is being sent.

After I associated a user to the form and matched the email address (form and global configuration), the form is back to working order!