Disable the PMPro Expiration Warning Emails

pmpro_send_expiration_warning_email.php

<?php // copy from below
/**
 * Disable the PMPro default expiration warning email
 * 
 * You can add this recipe to your site by creating a custom plugin
 * or using the Code Snippets plugin available for free in the WordPress repository.
 * Read this companion article for step-by-step directions on either method.
 * https://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/
 */

add_filter( 'pmpro_send_expiration_warning_email', '__return_false' );