<?php 
if(isset($_POST['submit'])){
    $to = "odfiafrica@gmail.com"; // this is your Email address
    $mailer = "admin@odfiafrica.com"; // this is your Email address
    $from = $_POST['email']; // this is the sender's Email address
    $name = $_POST['name'];
    $subject = "Odfi Tech Contact Form $name " ;
    $message = "Client's Name: " .$name . " \n\n".   "Wrote the following:" . "\n\n" . $_POST['message'];

    $headers = "From:" . $from;
    $headers2 = "From:" . $to;
    mail($to,$subject,$message,$headers);
    header('Location: http://tech.odfiafrica.com/fr/merci.html');
    // You can also use header('Location: thank_you.php'); to redirect to another page.
    // You cannot use header and echo together. It's one or the other.
    }
?>