leaky-paywall-add-receipt-to-email.php

<?php

add_filter('leaky_paywall_new_email_message', 'zeen_maybe_update_email_message', 99, 2);

function zeen_maybe_update_email_message($message, $user_id) {

    $user = get_user_by( 'ID', $user_id );
    $transaction_id = leaky_paywall_get_transaction_id_from_email( $user->user_email );
    $transaction = get_post($transaction_id);

    $level_id = get_post_meta( $transaction_id, '_level_id', true );
    $price = get_post_meta($transaction_id, '_price', true);
    $level = get_leaky_paywall_subscription_level($level_id);

    $html = '<table style="width: 100%"><tr><td><strong>Subscription to ' . $level['label'] . '</strong></td><td align="right"><strong>Sub total $' . $price . '</strong></td></tr></table>';
    $html .= '<hr>';
    $html .= '<table style="width: 100%"><tr><td>Total Tax</td><td align="right">$0.00</td></tr></table>';
    $html .= '<hr>';
    $html .= '<table style="width: 100%"><tr><td><strong>Total</strong></td><td align="right"><strong>$' . $price . '</strong></td></tr></table>';
    $html .= '<p>Paid on ' . date( 'M d, Y', strtotime($transaction->post_date) ) . '</p>';

    return $message . $html;

}