Description:
------------
mail() function returns boolean false but the email was recieved on the other end.

Test script:
---------------
<?php
error_reporting(E_ALL);
ini_set('display_errors', 1);
$to = 'mail@email.com'; // sample email
var_dump(mail( $to, 'checking mail return value', "It is just a test mail."));

// output : boolean false
// but mail is recieved at mail@email.com

Expected result:
----------------
boolean true

Actual result:
--------------
boolean false