What are some recommended mailer classes or services for sending styled HTML emails using PHP?

When sending styled HTML emails using PHP, it is recommended to use a mailer class or service that supports HTML content and styling. Some popular options include PHPMailer, Swift Mailer, and SendGrid. These classes provide easy-to-use methods for sending HTML emails with CSS styling.

// Example using PHPMailer
use PHPMailer\PHPMailer\PHPMailer;
use PHPMailer\PHPMailer\Exception;

require 'vendor/autoload.php';

$mail = new PHPMailer(true);

try {
    $mail->isHTML(true);
    $mail->Subject = 'HTML Email Test';
    $mail->Body = '<h1 style="color: blue;">Hello, this is a styled HTML email!</h1>';
    $mail->send();
    echo 'Email sent successfully';
} catch (Exception $e) {
    echo 'Message could not be sent. Mailer Error: ', $mail->ErrorInfo;
}