$whitepaper_message = array(
        "from" => "Tim O'Connor <*****@*****.**>",
        "to" => $name . " <" . $email . ">",
        "subject" => $whitepaper_subject,
        "html" => $whitepaper_body
    );
}

if($playbook) {
    $playbook_subject = "ResultsCI Playbook";

    $playbook_body = "
        <p>Dear " . $name . ",</p>
        <p>Thanks for connecting with Results.  Like other ambitious business leaders we work with, you are open to new ideas and concepts to help transform your business from good to great.</p>
        <p><a href='http://www.resultsci.com/wp-content/uploads/2016/04/RCi-Playbook-Template-blank-2016-03.pdf' target='_blank'>Here</a>, you will find our Playbook.  We trust you will find it valuable and look forward to your feedback.</p>
        <p>Thanks,<br><br>Tim O'Connor<br>Results Team</p>
    ";

    $playbook_message = array(
        "from" => "Tim O'Connor <*****@*****.**>",
        "to" => $name . " <" . $email . ">",
        "subject" => $playbook_subject,
        "html" => $playbook_body
    );
}

$mailgun->sendMessage($domain, $admin_message);
if($whitepaper) $mailgun->sendMessage($domain, $whitepaper_message);
if($playbook) $mailgun->sendMessage($domain, $playbook_message);

echo "success";
<?php

require "vendor/autoload.php";
use Mailgun\Mailgun;
$client = new \Http\Adapter\Guzzle6\Client();
$mailgun = new \Mailgun\Mailgun("key-bc4ddd510e0d9c6715dc581bb720b7ce", $client);
$domain = "mg.resultsci.com";
if ($_SERVER["HTTP_X_REQUESTED_WITH"]) {
    $name = htmlspecialchars($_POST["name"]);
    $email = htmlspecialchars($_POST["email"]);
    $subject = htmlspecialchars($_POST["subject"]);
    $message = htmlspecialchars($_POST["message"]);
    $to = "*****@*****.**";
    $mailgun->sendMessage($domain, array("from" => $name . " <" . $email . ">", "to" => "Tim O'Connor <" . $to . ">", "subject" => $subject, "html" => "<p>Connection Name: " . $name . "</p>" . "<p>Connection Email: " . $email . "</p>" . "<p>" . nl2br($message) . "</p>"));
    echo "success";
}