title: Php mail notification run with no error but cannot function
body: <p>my current php mail cannot be send out (<em>no error, all can run well, but only cannot send out notificant email</em>), and my code as attached.</p>
  
  <p><a href="https://i.stack.imgur.com/9WN9R.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/9WN9R.png" alt="enter image description here"></a></p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>if (isset($_POST["normal"])) { // check if normal leave form was submitted
    $insert = "INSERT INTO leave_applications (type, date_from, date_to, reason, days, submitted_on, notice, status, users_id)
    VALUES ('$type', '$ifrom', '$ito' , '$reason1' ,'$days', '$date', 'normal', 'Pending', '$id')";
  
    $headers  = 'MIME-Version: 1.0' . "\r\n";
    $headers .= 'Content-type: text/html; charset=utf-8' . "\r\n";
    $headers .= "From:" . "limwenwei1997@gmail.com". "\r\n";
    $headers .= "Cc: wenwei.lim@screamingtomatoes.com" . "\r\n";
  
  $message = '&lt;p&gt;&lt;strong&gt;This is strong text&lt;/strong&gt; while this is not.&lt;/p&gt;';
  
    $admin = "wenwei.lim@voodoocomms.com";
    $applicant = "limwenwei1997@gmail.com";
    $subject = "Tomato Portal: New Leave Submission";
  
  
  
  
    mail($admin,$subject,$message,$headers);
  
  
  
  
  } else {
    $insert = "INSERT INTO leave_applications (type, date_from, date_to, days, submitted_on, notice, status, users_id)
    VALUES ('$type', '$ifrom', '$ito' ,'$days', '$date', 'short', 'Pending', '$id')";
    $headers  = 'MIME-Version: 1.0' . "\r\n";
    $headers .= 'Content-type: text/html; charset=utf-8' . "\r\n";
    $headers .= "From:" . "limwenwei1997@gmail.com". "\r\n";
    $headers .= "Cc: wenwei.lim@screamingtomatoes.com" . "\r\n";
  
  $message = '&lt;p&gt;&lt;strong&gt;This is strong text&lt;/strong&gt; while this is not.&lt;/p&gt;';
  
    $admin = "wenwei.lim@voodoocomms.com";
    $applicant = "limwenwei1997@gmail.com";
    $subject = "Tomato Portal: New Leave Submission";
  
  
  
  
    mail($admin,$subject,$message,$headers);
  
  }</code></pre>
  </div>
  </div>
  </p>
  
  <p>Please someone help to reach me out,k thanks</p>