Are there any best practices or workarounds for handling SMTP connection limits imposed by hosting providers when using PHPMailer?

Many hosting providers impose limits on the number of SMTP connections that can be made within a certain timeframe when sending emails using PHPMailer. One workaround is to use a mailing queue system that batches emails and sends them in intervals to stay within the provider's limits. Another approach is to use a third-party SMTP service that allows for higher connection limits. 

// Example code snippet using a mailing queue system to handle SMTP connection limits
use PHPMailer\PHPMailer\PHPMailer;
use PHPMailer\PHPMailer\Exception;

// Code to add emails to a queue
$emails = array(
    'recipient1@example.com' => 'Subject 1',
    'recipient2@example.com' => 'Subject 2',
    'recipient3@example.com' => 'Subject 3',
);

foreach ($emails as $email => $subject) {
    // Add email to queue
}

// Code to send emails in batches
$batchSize = 10;
$interval = 60; // seconds

while (!empty($emails)) {
    $batch = array_slice($emails, 0, $batchSize, true);
    
    foreach ($batch as $email => $subject) {
        // Send email using PHPMailer
        $mail = new PHPMailer(true);
        $mail->isSMTP();
        $mail->Host = 'smtp.example.com';
        $mail->SMTPAuth = true;
        $mail->Username = 'your_smtp_username';
        $mail->Password = 'your_smtp_password';
        $mail->SMTPSecure = 'tls';
        $mail->Port = 587;
        $mail->setFrom('your_email@example.com', 'Your Name');
        $mail->addAddress($email);
        $mail->Subject = $subject;
        $mail->Body = 'This is the body of the email.';
        
        try {
            $mail->send();
            echo 'Email sent to ' . $email . PHP_EOL;
        } catch (Exception $e) {
            echo 'Message could not be sent. Mailer Error: ' . $mail->ErrorInfo . PHP_EOL;
        }
        
        // Remove email from queue
        unset($emails[$email]);
    }
    
    sleep($interval);
}

Keywords

PHP PHPMailer SMTP hosting providers connection limits

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