-mb_send_mail()- PHP Why isn't email sent to my email address? No error [duplicate]

I want to execute in PHP to send emails in Japanese, but email hasn't been sent although there's no error. This is what I wrote below:

<?php
    $to = "sanae@gmail.com";
    $subject = "入力がありました！";
    $message = "入力です";
    $from = "text@example.com";

    mb_language("Japanese");
    mb_encode_mimeheader("UTF-8");
    mb_send_mail($to, $subject, $message, "From:" .$from);
    ?>

Thank you in advance!