Need to correct my existing HTML enquiry form

Hello, I have an easy task. My website enquiry form seen here: [login to view URL] Has stopped working because the matt's FormMail system has gone down, or the server isn't running the script anymore. I need to re-write my existing form code so that it doesn't use the FormMail. Maybe you can use another method to send the form like PHP mailer or something. Note: All the fields must stay the same. I just need to change the way it gets sent to me. You will also need to explain to me the way you will be doing the changes. Thank you.