PHP 電子メール検出: 電子メールが正常に送信されたかどうかを判断します。

require 'path/to/phpmailer/autoload.php';

use PHPMailerPHPMailerPHPMailer;
use PHPMailerPHPMailerException;

$mail = new PHPMailer(true);
try {
    $mail->SMTPDebug = 0;                                 // Enable verbose debug output
    $mail->isSMTP();                                      // Set mailer to use SMTP
    $mail->Host = 'smtp.example.com';                      // Specify main and backup SMTP servers
    $mail->SMTPAuth = true;                               // Enable SMTP authentication
    $mail->Username = 'your-email@example.com';           // SMTP username
    $mail->Password = 'your-email-password';              // SMTP password
    $mail->SMTPSecure = 'tls';                            // Enable TLS encryption, `ssl` also accepted
    $mail->Port = 587;                                    // TCP port to connect to

    $mail->setFrom('your-email@example.com', 'Your Name');
    $mail->addAddress('recipient@example.com', 'Recipient Name');
    $mail->isHTML(true);                                  // Set email format to HTML
    $mail->Subject = 'Test Subject';
    $mail->Body    = 'This is a test email.';

    $mail->send();
    echo 'Email has been sent.';
} catch (Exception $e) {
    echo 'Email could not be sent. Error: ', $mail->ErrorInfo;
}

if ($mail->send()) {
    $response = $mail->getSMTPInstance()->getLastResponse();
    if (preg_match('/^250/', $response)) {
        echo 'Email has been sent.';
    } else {
        echo 'Email could not be sent. Response: ' . $response;
    }
} else {
    echo 'Email could not be sent. Error: ', $mail->ErrorInfo;
}

$mail->addCustomHeader('Return-Receipt-To: your-email@example.com');
$mail->addCustomHeader('Disposition-Notification-To: your-email@example.com');

if ($mail->send()) {
    echo 'Email has been sent.';
} else {
    echo 'Email could not be sent.';
}