Small php script which will reassign orders to the correct customers

fixorders.php

<?php

require_once('../../app/Mage.php'); //Path to Magento
umask(0);
Mage::app();

error_reporting(E_ALL);
ini_set('display_errors', 1);
ini_set('max_execution_time', 3000);
echo '<pre>';

$fromDate = date('Y-m-d H:i:s', 1420070400);
$toDate = date('Y-m-d H:i:s', 1443526700);

$_filename = 'check.log';

$_orders = Mage::getModel('sales/order')->getCollection()
	->addAttributeToFilter('created_at', array('from' => $fromDate, 'to' => $toDate));

$_customerModel = Mage::getModel("customer/customer");
$_customer = false;

foreach($_orders as $_order):
		$_check = 'false';
		if($_order->getCustomerId() !== NULL):
			$_customer = $_customerModel->setWebsiteId(Mage::app()->getStore()->getWebsiteId())->load($_order->getCustomerId());
			$_logstring = 'Orderid: '.$_order->getIncrementId().' - OrderEmail: '.$_order->getCustomerEmail().' - CustomerEmail: '.$_customer->getEmail();
			if($_customer->getEmail() == $_order->getCustomerEmail()):
				$_check = 'true';
			else:

				$_orderCustomer = $_customerModel->setWebsiteId(Mage::app()->getStore()->getWebsiteId())->loadByEmail($_order->getCustomerEmail());
				if($_orderCustomer && $_orderCustomer->getEntityId()):
					$_order->setCustomerId($_orderCustomer->getEntityId());
					$_order->save();
				endif;

				$_logstring .= ' - CustomerID: '.$_customer->getEntityId().' - OrderCustomerID: '.$_orderCustomer->getEntityId();
				$_check = 'ERROR';
			endif;
		else:
			$_customer = false;
			$_logstring = 'Orderid: '.$_order->getIncrementId().' - OrderEmail: '.$_order->getCustomerEmail().' - CustomerEmail: no Customer';
		endif;

		Mage::log($_logstring, null, $_filename);

		Mage::log($_check, null, $_filename);
		Mage::log('------------------------', null, $_filename);
endforeach;

echo 'finish';
die();