Paid Memberships Pro - Ban Email Domains

pmpro-ban-email-domains.php

<?php
function pmpro_custom_banned_domains( $continue_registration ) {
	global $pmpro_msg, $pmpro_msgt;
	if ( isset ( $_REQUEST['bemail'] ) ) {
		$bemail = sanitize_email( stripslashes( $_REQUEST['bemail'] ) );
		$banned_email_domains = array(
			'.ru', /* Add more email domains here */
		);
		foreach ( $banned_email_domains as $domain ) {
			if ( strstr( $bemail, $domain ) ) {
				$pmpro_msgt = 'pmpro_error';
				$pmpro_msg = 'The email you entered is invalid.';
				return false;
			}
		}
	}
	return $continue_registration;
}
add_filter( 'pmpro_registration_checks', 'pmpro_custom_banned_domains', 10, 1 );