Does the PHP mail function return true if email is incorrect
<p>I am making a system that will be used to collecting a larger of data from users. I know some will be spam! I just want to know if the mail function returns false if the email is not correct? </p>

<p>Say I have. </p>

<pre><code>   &lt;?php

    $to = "fake@fake.com";
    $header = "From: {$to}";
    $subject = "Hi!";
    $body = "Hi,\n\nHow are you?";

    if (mail($to, $subject, $body, $header)) {
          echo("&lt;p&gt;Message successfully sent!&lt;/p&gt;");
    } else {
          echo("&lt;p&gt;Message delivery failed...&lt;/p&gt;");
    }

   ?&gt;
</code></pre>

<p>Which message will be printed if the email is not correct?</p>

<p>If it does return false I want a "flag" to be stored with it in that database so the admins can review it and delete it. </p>
