Você precisa criar um plug-in para salvar o e-mail do cliente no armazenamento local. Então, adicione uma configuração de plugin de frontend em di.xml
<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
<type name="Magento\Customer\CustomerData\Customer">
<plugin name="additional_section_data" type="Your\Module\Plugin\AddCustomerEmail" />
</type>
</config>
E o plugin ficará assim:
<?php
namespace Your\Module\Plugin;
use Magento\Customer\Helper\Session\CurrentCustomer;
class AddCustomerEmail
{
/**
* @var CurrentCustomer
*/
private $currentCustomer;
public function __construct(
CurrentCustomer $currentCustomer
) {
$this->currentCustomer = $currentCustomer;
}
public function afterGetSectionData(\Magento\Customer\CustomerData\Customer $subject, $result)
{
if ($this->currentCustomer->getCustomerId()) {
$customer = $this->currentCustomer->getCustomer();
$result['email'] = $customer->getEmail();
}
return $result;
}
}