Need code location for email send

Where would I go in and change the code to get this to work with Godaddy email and Gmail?
So if I could just find where to put this code, I’d be set! Thanks.
$mail = new PHPMailer();
$mail->IsSMTP();
$mail->isHTML(true);
$mail->Host = “smtpout.secureserver.net”;
$mail->SMTPAuth = true;
$mail->Port = 25;
$mail->Username = “email@godaddy.com”;
$mail->Password = *******;
$mail->Subject = “Test Email”;
$mail->SMTPDebug = 1;