How to send e-mail to multiple recipients without limit

Question

I want to use php to send email to many e-mail addresses but:

1. I want to make 30 seconds delay between every sent email
2. I don't want limit to recipients list (my list is over 500 email) when I run the code it tells my time out after 30+ sent email

this is the code I use so far hope if you can help

<?php
$EmailsDB = file('emails.txt');
$from     = "[email protected]";
$fromName = "Website Name";
$subject  = "Subject";
$header = "MIME-Version: 1.0" . "\r\n"; 
$header .= "Content-type:text/html;charset=UTF-8" . "\r\n";
$header .= 'From: '.$fromName.'<'.$from.'>' . "\r\n"; 
$message = file_get_contents("message.html");
            
foreach ($EmailsDB as $to) {
    if(mail($to, $subject, $message, $header)) {echo"E-mail sent successfully to $to <br />";}
    else {echo"Sorry, failed while sending!";}
}
?>

Hope to find the answer here, kind regards