A plugin that disables all WordPress emails sent using wp_mail()

disable-email.php

<?php
/**
 * Plugin Name: Disable Email
 * Plugin URI: https://www.tannerrecord.com/micro-plugins/disable-email
 * Description: A plugin that disables all email sent using <code>wp_mail()</code>.
 * Author: Tanner Record
 * Author URI: https://www.tannerrecord.com
 * Update URI: false
 * Version: 1.0
 */

add_filter( 'pre_wp_mail', 'tarecord_disable_email' );

function tarecord_disable_email() {
    do_action( 'wp_mail_succeeded' );
    return true;
}