Foreach function gives 503 Service Unavailable - php

Question

It is 1 AM and I am struggling for 3-4 hours to see what's wrong with my script...
My database has ~400 emails. I set $ChunkSize as counter for the loop and also to count which is the next chunk to be processed.
I've set some echo() to debug
echo "This is the " . $GLOBALS["ChunkSize"] . " chunk. <br>";
It should output what chunk is processed at that time.
If I disable mail() then I don't get 503 Service Unavailable but every echo() displays at the same time, not in the order of processing.
I also found out that some emails arrive, but not to everyone. Also, if some emails are sent, that means foreach() should have processed at least one chunk, that means it should display at least one echo().
I've set break 1; so every time it breaks out of foreach() it should display the echo() with the chunk number processed by foreach() but it doesn't.
What I am doing wrong?
$connection = mysql_connect($hostname, $username, $password);
mysql_select_db($dbname, $connection);
$result = mysql_query("SHOW COLUMNS FROM `Emails`");
while($row = mysql_fetch_array($result)){
$Addresses[] = $row['Field'];}
$Subject = "Test";
$Message = "
Test
";
$Headers = array( EMPTY FOR SECURITY REASONS );
$Headers = implode( "\r\n" , $Headers );
$ChunkAddresses = 50;
$EmailChunkArray = array_chunk($Addresses, $ChunkAddresses);
$ArraySize = count ($EmailChunkArray);
$ChunkSize = 0;
ChunkLoop: {
$EmailChunkArrayLoop = $GLOBALS["EmailChunkArray"];
foreach ($EmailChunkArrayLoop[$GLOBALS["ChunkSize"]] as $ToChunkLoop) {
if ($GLOBALS["ChunkSize"] <= $GLOBALS["ArraySize"]) {
mail($ToChunkLoop,$GLOBALS["Subject"],$GLOBALS["Message"],$GLOBALS["Headers"]);
echo "This is the " . $GLOBALS["ChunkSize"] . " chunk. <br>";
} else if ($GLOBALS["ChunkSize"] == $GLOBALS["ArraySize"]){
exit();}
$GLOBALS["ChunkSize"]++;
break 1;}
}
if ($GLOBALS["ChunkSize"] != $GLOBALS["ArraySize"]){
echo "Test. <br>";
goto ChunkLoop;
} else {
echo "Finished! <br>";}

Answer 1

Create script that will only do one thing - send mail.
sendMail.php
<?php
// Get recipient from the argv array
$recipient = $_SERVER['argv'][1];
// Mail args
$subject = 'HELLOOOOOOO';
$message = 'BLablabla';
$headers = [...]; // optional or not
// Send it
mail($recipient, $subject, $message, $headers);
And inside of Your code where You do:
mail($ToChunkLoop,$GLOBALS["Subject"],$GLOBALS["Message"],$GLOBALS["Headers"]);
Replace with:
$recipient = escapeshellarg($ToChunkLoop);
exec("php /path/to/sendMail.php ".$recipient." > /dev/null &"); // that will call mail script and will not wait when execution will end
Feel free to adapt my code examples as You wish
P.S. this solution is for cases when You don't want to pay for normal batch mail sending, mail subscription or dedicated, vps services and have just small web hosting. (:
P.S.. it's not a brilliant solution, but done for requirements provided by question author