user_email_validation_test.module

<?php


/**
 * @file
 * Dummy module implementing hook_valid_email_address_alter.
 */

/**
 * Implements hook_valid_email_address_alter().
 */
function user_email_validation_test_valid_email_address_alter(&$valid, $mail) {
    $local = '.local';
    // Invalidate all e-mails ending with .local.
    if (substr_compare($mail, $local, -strlen($local)) === 0) {
        $valid = FALSE;
    }
}