如何向phpmailer添加表单验证？

Question

I am a newbie to PHP, and I am currently using phpmailer to let my clients send emails to me, but a bot is apparently taking advantage of it and sends 3 emails at exactly the same time everyday. So I've been trying to add validation to the form using PHP as javascript can be stopped to avoid validation.. Could you guys please help me add validation to this? I just need to validate name and email. Thank you so much in advance.

PS. I removed some parts of the code for privacy.

<?php

require 'PHPMailerAutoload.php';

$mail = new PHPMailer;

    $name = $_POST['name'];
    $email = $_POST['email'];
    $phone = $_POST['phone'];
    $address = $_POST['address'];
    $proptypes = $_POST['proptypes'];
    $units = $_POST['units'];
    $purchaseOrRefi = $_POST['purchase'];
    $loans = $_POST['loans'];
    $income = $_POST['income'];
    $apt = $_POST['apartment'];
    $message = $_POST['message'];
    $body = "<b>[From]</b><br>$name<br><br> <b>[E-Mail]</b><br>$email<br><br> <b>[Phone #]</b><br>$phone<br><br> <b>[Address]</b><br>$address<br><br> <b>[Type of Property]</b><br>$proptypes<br><br> <b>[# of Units]</b><br>$units<br><br> <b>[Purchase or Refi?]</b><br>$purchaseOrRefi<br><br> <b>[Amnt of Loans Requested]</b><br>$loans<br><br> <b>[Total Income]</b><br>$income<br><br> <b>[Total Apt Expense]</b><br>$apt<br><br> <b>[Message]</b><br>$message<br><br>";


$mail->Subject = 'Someone wants to hear more about your mortgage programs!';
$mail->Body = $body;
$mail->From = '';
$mail->FromName = '';
 // Add a recipient
$mail->addAddress('');  
$mail->addAddress('');
$mail->addAddress('');              

$mail->addAttachment($_FILES['attachment']['tmp_name'], $_FILES['attachment']['name'], 'base64', $_FILES['attachment']['type']);         // Add attachments

$mail->isHTML(true);  

if(!$mail->send()) {
    echo 'Message could not be sent. Please try again.';
    echo 'Mailer Error: ' . $mail->ErrorInfo;
} else {
    echo 'Your message has been sent! We will get back to you soon!';
}

?>