Protecting Your PHP Web App From Disposable Email Users via DEA-filter http://w3guy.com/protect-php-app-disposable-email/

deaFilterClient.php

<?php

function checkDEAfilter($deaEmailToCheck)
{ 
$apiKey = "5a8047b40e57750726618b8146066ef6"; // change to your API key

$curlPost = "mail=" . $deaEmailToCheck."&key=".$apiKey; //address to check

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "http://www.deafilter.com/classes/DeaFilter.php"); //must point to the DeaFilter.php class
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $curlPost);
curl_setopt($ch, CURLOPT_VERBOSE,0);
$data = curl_exec($ch);
curl_close($ch);

$data = json_decode($data);


if ($data->result != "ok")
{
    return false;
} else
{
    return true;
}
}

index.php

<?php include "deaFilterClient.php";?>

<form action="" method="post">
<label for="male">Email Address</label><br/>
<input type="text" name="email" id="email" value="<?php echo (isset($_POST["email"])) ? $_POST["email"] : "";?>"/>
<?php 
// validate and detect if email is disposable or not
if (isset($_REQUEST["email"])) 
            { 
    if ( !checkDEAfilter($_REQUEST["email"])) {?>
     <img src="images/cancel.png"/> &nbsp; &nbsp; <input type="submit" value="validate"/> <?php } 
else echo '<img src="images/accept.png"/>';} else echo '<input type="submit" value="validate"/>';
?>
    <br/><br/>
    <input type="submit" name="submit" value="submit form"/>
    </form>
// validate the form before sent to the server for processing
// Check if email is set and if it not disposable
<?php if((isset($_REQUEST["submit"])) && (checkDEAfilter($_REQUEST["email"]))) {
        echo "your email is " . $_REQUEST['email'] ;
        }
        ?>