public function getListGroupEmail($groupDn = null) {
		$result = [];
		if (empty($groupDn)) {
			return $result;
		}

		$cacheKey = md5($groupDn);
		$cached = Cache::read($cacheKey, CAKE_SETTINGS_APP_CACHE_KEY_AD_GROUP_MEMBER_MAIL);
		if (!empty($cached)) {
			return $cached;
		}

		$conditions = '(&(userAccountControl:1.2.840.113556.1.4.803:=512)(!(useraccountcontrol:1.2.840.113556.1.4.803:=2))(objectClass=user)(' . CAKE_SETTINGS_APP_LDAP_ATTRIBUTE_MEMBER_OF . '=' . $groupDn . '))';
		$fields = [CAKE_SETTINGS_APP_LDAP_ATTRIBUTE_NAME, CAKE_SETTINGS_APP_LDAP_ATTRIBUTE_MAIL];
		$order = CAKE_SETTINGS_APP_LDAP_ATTRIBUTE_MAIL;

		$data = $this->find('all', compact('conditions', 'fields', 'order'));
		if (empty($data)) {
			return $result;
		}

		foreach ($data as $dataItem) {
			$mail = Hash::get($dataItem, $this->alias . '.' . CAKE_SETTINGS_APP_LDAP_ATTRIBUTE_MAIL);
			$name = Hash::get($dataItem, $this->alias . '.' . CAKE_SETTINGS_APP_LDAP_ATTRIBUTE_NAME);
			if (empty($mail)) {
				continue;
			}
			$result[$mail] = $name;
		}
		Cache::write($cacheKey, $result, CAKE_SETTINGS_APP_CACHE_KEY_AD_GROUP_MEMBER_MAIL);

		return $result;
	}