PHP Mass mailer not sending all mail

Question

so what I am doing is coding a script for me to personally stress test my softwares ability to recieve emails (I am working on a simple email client). Basically, it should just send as many emails as I tell it to send to my email address. Here is the code:

$i=0; 
while ($i < $numberofemails) { 
        $m = rand(10e16, 10e20);

    $n = base_convert($m, 10, 36);

$subject = 'Test';

mail("myemail@gmail.com", $subject, $message, null, "-f" . $n . "@mydomain.com"); 
$i++; 
} 

The script works, but it does not send all of the emails that I tell it to (or atleast recieve all the emails.) It ussually only recieves less then half, and then sometimes it will recieve some, then a few hours later randomly recieve a few more. Any idea why this happens? I tried it with gmail and AOL also. Is there a better way to send email for this?

Answer 1

There's nothing in the script that would give the required information to diagnose the issue. You'd have to watch the traffic or look in mail logs.

Note that many destinations rate-limit people who try to send to them, including gmail, aol, and many others. If you suddenly start sending significantly more email in a short period of time than you normally do, then they'll make you wait before sending more. The actual limits are generally secret and seem to vary based on your behavior.