Valida E-mail e domínio

function validaEmail($email){
	if(filter_var($email, FILTER_VALIDATE_EMAIL))
	{
		$separa = list($usuario, $provedor) = explode('@', $email);
		if(getmxrr($separa[1], $mx_records, $mx_weight))
			return $separa[0].'@'.$separa[1];
		else
			return false;
	}
	return false;
}

echo validaEmail('jotape_pinheiro@hotmail.com');