Too many redirects sending email via phpmailer - php

Question

I have a table in the db that queues and stores all the mails that are sent through a script that inserts data into this table.
Another script in php manages the sending, given the high number of emails, to avoid spamming it sends them in groups of 50.
it repeats the loop until all the tuples have been sent.
(there is a column for each tuple with queued or sent set)
The problem is the following:
Given, precisely, the high number of submissions, at a certain point the script crashes (chrome) with the error "ERR_TOO_MANY_REDIRECTS".
How can i resolve?
<?php
require_once '../dbh.inc.php';
include_once '../functions.php';
error_reporting(E_STRICT | E_ALL);
date_default_timezone_set('Etc/UTC');
require '../PHPMailer/PHPMailerAutoload.php';
$mail = new PHPMailer;
$mail-> isSMTP();
$mail->Host = 'smtps.*****.it';
$mail->SMTPDebug = 0;
$mail->Port = 465;
$mail->SMTPAuth = true;
$mail->SMTPAutoTLS = false;
$mail->SMTPSecure = 'ssl';
$mail->Username = 'intranet#*****.it';
$mail->Password = '*****';
$mail->Priority = '1';
$mail->setFrom('intranet#*****.it', '*****');
$process_count = 50;
$sql = "SELECT * FROM `email_queue` WHERE `status` = 'queued' AND `do_not_send_before` < '" .strtotime("now") ."'
ORDER BY `submission_date`, `priority` ASC LIMIT $process_count ";
$result = mysqli_query($conn, $sql);
foreach ($result as $row) {
$mail->addAddress($row['recipient']);
$mail->addReplyTo($row['reply_to']);
$mail->IsHTML(true);
$mail->CharSet = "UTF-8";
$mail->Subject = $row['subject'];
$mail->msgHTML($row['message']);
$mail->AltBody = "";
$file1 = $row['file1'];
$file2 = $row['file2'];
$file3 = $row['file3'];
$file4 = $row['file4'];
$file5 = $row['file5'];
$filepath = '/web/htdocs/www.*****.it/home/it/intranet/uploads/mails/';
if (!empty($file1)) {
$file1 = $filepath.$file1;
$mail->AddAttachment($file1);
}
if (!empty($file2)) {
$file2 = $filepath.$file2;
$mail->AddAttachment($file2);
}
if (!empty($file3)) {
$file3 = $filepath.$file3;
$mail->AddAttachment($file3);
}
if (!empty($file4)) {
$file4 = $filepath.$file4;
$mail->AddAttachment($file4);
}
if (!empty($file5)) {
$file5 = $filepath.$file5;
$mail->AddAttachment($file5);
}
if (!$mail->send()) {
echo "Mailer Error (" . str_replace("#", "#", $row["recipient"]) . ') ' . $mail->ErrorInfo . '<br />';
break; //Abandon sending
} else {
$now = strtotime("now");
//echo "Messaggio inviato a :" . ' (' . str_replace("#", "#", $row['recipient']) . ')<br />';
//Mark it as sent in the DB
$sql1 = "UPDATE `email_queue` SET `status` = 'sent', `sent_date` = '$now' WHERE `id` = '" . $row['id'] . "'";
$result = mysqli_query($conn, $sql1);
if ($result) {
echo "Mail Inviata correttamente a: (" . str_replace("#", "#", $row["recipient"]) . ') <br />';
} else {
echo "error $sql1 </br>";
}
}
// Clear all addresses and attachments for next loop
$mail->clearAddresses();
$mail->clearAttachments();
}
$sql2 = "SELECT COUNT(*) AS count FROM `email_queue` WHERE `status` = 'queued';";
$result2 = mysqli_query($conn, $sql2);
$row2 = mysqli_fetch_assoc($result2);
$count = $row2['count'];
echo "$count";
if ($count > 0) {
header('Location: '.$_SERVER['PHP_SELF']);
} else {
header('Location:' . $USER_LOCATION . "index.php?emails=success");
}
?>

Answer 1

At the end of script, you have else-if condition which always results in a redirect. If the count of rows is bigger than 0, you redirect it to the same script, without end. It results in a never-ending loop of redirects.
Just do not redirect in this case, or redirect to another script that won't redirect to another (or the same) script again.
pseudo code:
if ($count > 0) {
// do something here instead of redirect
} else {
header('Location:' . $USER_LOCATION . "index.php?emails=success");
}

Answer 2

header('Location: '.$_SERVER['PHP_SELF']); always redirects to same URL and there server sees infinite redirect, that's why TOO_MANY_REDIRECTS.
Do not use re-directs here. Use loop.
do {
$count = $this->getCount();
if ($count > 0) {
$this->processEmails();
}
} while ($count > 0);
Note that this process may be executed longer than 30s and it would time out your ordinary browser request. Use it as CLI command