Question

I want to limit sending email 90 email per hour using php code

Answer 1

You can use PHP to do it in this very hackish way:

Create a blank file called count_offset.txt
This will be a file that tracks the offset of the chunked set of 90 users.

Create another blank file called count_emails.txt
This will be a file that tracks the number of emails sent in the particular hour.

The PHP script that runs the email function (thru cron) can then open up this first text file to check which chunked set has been sent, and sends to the next set of users. It can check the second file for the 90 email limit.

For example:

$userCount = getNumberOfUsers(); // Whatever query you may have that counts how many total users there are.

$numChunks = ceil($userCount/90); // How many different groups to send the email.

$chunkFile = fopen('chunk_offset.txt', 'r+'); // Loads the file as resource.
$currentChunk = fread($chunkFile, filesize('chunk_offset.txt')); // Load the contents of chunk_offset.txt into variable.
$currentChunk = ($currentCount == '' ? 0 : (int)$currentChunk); // Load 0 if contents of file blank.

$countFile = fopen('count_emails.txt', 'r+'); // Loads the file as a resource in variable $countFile.
$currentCount = fread($countFile, filesize('count_emails.txt')); // Load the content of the file into variable $currentCount.
$currentCount = ($currentCount == '' ? 0 : (int)$currentCount); // If the value of $currentCount is blank, then sets it to integer 0, otherwise sets the variable as the integer value of file contents.

if ($currentCount <= 90) // Test the variable to see if it's under the limit. If it's under, send the email.
{
    foreach ($whateverUserListYouHave as $integerKey => $emailAddress) // Iterating through whatever array of users you have.
    // Hopefully index number => email, but the index number is important.
    // Also, consistent ordering of the list of users is important.
    // Remember, you can always create your own counter.
    {
        // The magic:
        // You're testing for set of people who fall within the current chunk.
        if ($integerKey >= ($currentChunk * 90) && $integerKey < ($currentChunk * 90 + 90))
        {
            send_email($emailAddress); // Whatever arbitrary email function you have here.
        }
    }
}

$currentCount++; // Iterate up the count.
fwrite($countFile, $currentCount); // Write the new count into the file.

if ($currentChunk == $numChunks) // If the current chunk number hits the total number of groups of 90, then reset the file to blank...
{
    $currentChunk = '';
}
else if ($currentChunk < $numChunks) // ... Otherwise iterate up and let it hit the next chunk on the next hour.
{
    $currentChunk++; // Iterate up the chunk.
}
fwrite($chunkFile, $currentChunk);

Afterwards, write another cron that clears the count_emails.txt file every hour (or turns the contents to 0). This other cron can run another PHP script or can be a Bash command if you prefer.

Here would be the cron if you wanted to do it using Bash commands:

0 * * * * cat /dev/null > count_emails.txt

The above line when added to cron, with use cat to clear the contents of the count_emails.txt file.

Cheers, and good luck!