Simplest way is to use PHPMailer and Gmail SMTP. The configuration would be like the below.
require 'PHPMailer/PHPMailerAutoload.php';
$mail = new PHPMailer;
$mail->isSMTP();
$mail->Host = 'smtp.gmail.com';
$mail->SMTPAuth = true;
$mail->Username = 'Email Address';
$mail->Password = 'Email Account Password';
$mail->SMTPSecure = 'tls';
$mail->Port = 587;
Example script and full source code can be found from here - How to Send Email from Localhost in PHP