Website Script: Send mail from existing HTML form

Hello, Fairly simple project here. I have a website with two existing contact forms. These forms have three fields each and both have a "submit" button. I need the appropriate scripts that will allow people to fill out these forms hit "submit" and have the results e-mailed to a specific address. When it is all said and done the desired functions must be met - 1. Will not allow invalid e-mail address (email address required) 2. Confirmation message once the "submit" button is pushed 3. All form information is e-mailed to desired email address 4. Must be 100% mobile and tablet friendly and up to the quality standards of the existing site **NOTE: THE FORMS ALREADY EXIST, ALL THAT IS NEEDED IS A SCRIPT TO MAKE THEM WORK This project is fairly simple and straightforward. Website project files are attached. Thanks!