Stripe get customer email address - stripe-payments

Question

I'm trying to yet up a subscription using Stripe checkout.js and then using PHP to Subscribe customers. My problem is getting their email address. Can't find anything useful in the docs.
Docs here: https://stripe.com/docs/guides/subscriptions#step-2-subscribe-customers
What I have:
<script src="https://checkout.stripe.com/checkout.js"></script>
<button id="customButton">Purchase</button>
<script>
var handler = StripeCheckout.configure({
key: 'pk_test_keyhere',
image: '/square-image.png',
token: function(token) {
// Use the token to create the charge with a server-side script.
// You can access the token ID with `token.id`
}
});
document.getElementById('customButton').addEventListener('click', function(e) {
// Open Checkout with further options
handler.open({
name: 'test2',
description: 'Test Des',
amount: 0001,
currency:'GBP'
});
e.preventDefault();
});
</script>
<?php
// Set your API key
Stripe::setApiKey("sk_test_keyhere");
$token = $_POST['stripeToken'];
$customer = Stripe_Customer::create(array(
"card" => $token,
"plan" => "test2",
"email" => $email
)
);
?>

Answer 1

Adding to David's answer, you can retrieve the email address via PHP like so:
$stripeinfo =Stripe_Token::retrieve($_POST["token"]);
echo '<pre>',print_r($stripeinfo),'</pre>'; //show stripeObject info
$email = $stripeinfo->email;
Adding a small update to this answer for people who are coming across this now.
$token = $_POST['stripeToken'];
$stripeinfo = \Stripe\Token::retrieve($token);
$email = $stripeinfo->email;
$customer = \Stripe\Customer::create(array(
'email' => $email,
'source' => $token,
'description' => 'New Customer'
));
Just some small changes I had to make to get my code to work.

Answer 2

If you are using Checkout you will be passed a token, using that token you can obtain the email address through an API call: https://stripe.com/docs/api#retrieve_token
Not sure why email isn't listed under there but I do have an email attribute available to me. You can also see the email under the Stripe's logs.