CMailDomain2::isUserExists

static function isUserExists($token, $domain, $login, &$error)
{
	$result = CMailYandex2::checkUser($token, $domain, $login, $error);

	switch ($result)
	{
		case 'exists':
			return true;
		case 'nouser':
			return false;
		default:
			$error = self::getErrorCode($error);
			return null;
	}
}