email_templates.xml

<?xml version="1.0"?>
<!--
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
-->
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Email:etc/email_templates.xsd">
    <template id="newsletter_subscription_confirm_email_template" label="Subscription Confirmation" file="subscr_confirm.html" type="html" module="Magento_Newsletter" area="frontend"/>
    <template id="newsletter_subscription_success_email_template" label="Subscription Success" file="subscr_success.html" type="html" module="Magento_Newsletter" area="frontend"/>
    <template id="newsletter_subscription_un_email_template" label="Unsubscription Success" file="unsub_success.html" type="html" module="Magento_Newsletter" area="frontend"/>
</config>