Failed to send email with phpmailer

I use PHPMAILER on another site where it works perfectly. However, this same code does not allow me to send emails, it gives Sucesso and no error appears. I used the code $mail->SMTPDebug = 2; and I can not find any errors there.

Here is the code

require 'mail/PHPMailerAutoload.php';
    $mail = new PHPMailer();
    $mail->IsSMTP();   
    $mail->SMTPDebug = 2;  
    $mail->Host = "servidor";  //nome do servidor está oculto
    $mail->Port = 587;
    $mail->SMTPAuth = false;
    $mail->CharSet="utf-8";

    $mail->From = "email1";
    $mail->FromName = "Nome1";
    $mail->AddAddress("email2");
    $mail->IsHTML(true);

    $mail->Subject = "Taasd";
    $mail->Body    = $titulo;

    if(!$mail->Send()){
       echo "<script>console.log('".$mail->ErrorInfo."')</script>";
       exit;
    }else{
        echo "<script>console.log('Sucesso')</script>";
    }