blackdogruns

So i have a small mail form for contact purposes on my webpage and recently somebody spammed it, in which broke one of the terms of use for 000webhost,"mass e-mail". I want to make some sort of spamcheck to make sure that people aren't using it for spamming purposes, and if they do, then it will rout them to a different page telling them that they should not Spam... or something of the sort... any ideas?
Here is my original php.

<?php
$files = $_REQUEST['upload'];
$name = $_REQUEST['Name'];
$email = $_REQUEST['Email'] ;
$subject = "Frabah " . $_REQUEST['Name'] ;
$message = "Name: " . $_REQUEST['Name'] . " " . "\nEmail: " . $_REQUEST['Email'] . " " . "\nusername: " . $_REQUEST['Usr'] . " " . "\nmember: " . $_REQUEST['member'] . " " . "\njob: " . $_REQUEST['job'] . " " . "\nmessage: " . $_REQUEST['Input'] ;

@mail("theepicwebaster@yahoo.com", "$subject", $message, "From:" . $email );
echo "Hello $name Thank you for filling out my mail form<br> An e-mail has" ;
echo "been dispatched to myself and i will reply shortly to your e-mail $email ";
echo "Have a nice day";
?>