email_extended.php

<?php
//For PHP 5.3.x or later
public function emailExtended($data, $deep = false) {
    $pattern = '/.+@(docomo|ezweb)\.ne\.jp$/i';
    $check = preg_replace_callback($pattern, function($matches) {
        $patterns = array('/\.{2,}/', '/\.@/');
        $replacements = array('.', '@');
        return preg_replace($patterns, $replacements, $matches[0]);
    }, array_shift($data));
    return Validation::email($check, $deep);
}

email_extended_52.php

<?php
//For PHP 5.2.x or earlier
public function emailExtended($data, $deep = false) {
    $pattern = '/.+@(docomo|ezweb)\.ne\.jp$/i';
    $check = preg_replace_callback($pattern, create_function('$matches', '
        $patterns = array("/\.{2,}/", "/\.@/");
        $replacements = array(".", "@");
        return preg_replace($patterns, $replacements, $matches[0]);
    '), array_shift($data));
    return Validation::email($check, $deep);
}