Setting amount of time to pass when sending emails in a loop

Question

Forgive me for this noob question, but is there such a setting that sets a certain amount of time (e.g. milli/seconds) that has to pass in between sending emails through a script? How is that setting called and where do I change that setting?

I'll give an example: I used to have a PHP script that sends emails like so:

for ($i=0; $i<count($emails); $i++) {
     mail($email[$i],'test','test');
}

It turned out that not all emails were sent successfully because the script ran so fast that there was not enough time in between sending emails that was required by the server.

Did I make sense?

Answer 1

You can use one of these functions to do nothing for a while :

• sleep() : Delays the program execution for the given number of seconds.
• usleep() : Delays program execution for the given number of micro seconds.

Putting one of those in your loop should help.
For example :

for ($i=0; $i<count($emails); $i++) {
    mail($email[$i],'test','test');
    usleep(100*1000); // 100 milli-seconds
}

Answer 2

This script is untested but the theory is sound. Upon each send mail, check with a delay sequence to see if the mail has sent. I've set a limit to ensure the script does not fail - with the print, the execution time shouldn't be a problem.

for ($i=0; $i<count($emails); $i++) {
   $sent = mail($email[$i],'test','test');
    $count = 0;

   while($sent == false) {
    usleep(500); // half a second - test this number until the minimum is found
    $count++;

    if($count == 1000) {
        echo "Email to " . $email[$i] . " failed due to timeout</br>";
        break;
    }
   }
}

does that help?