PHP Mail 详细解读：深入了解邮件发送的技术细节

ini_set("SMTP", "mail.example.com");
ini_set("sendmail_from", "info@example.com");

$to = "recipient@example.com";
$subject = "测试邮件";
$message = "这是一封测试邮件。";
$headers = "From: sender@example.com
";

mail($to, $subject, $message, $headers);

require_once "Mail.php";
require_once "Mail/mime.php";

$to = "recipient@example.com";
$subject = "测试邮件";
$message = "这是一封带有附件的测试邮件。";

$from = "sender@example.com";
$host = "smtp.example.com";
$username = "username";
$password = "password";

$headers = array(
    'From' => $from,
    'To' => $to,
    'Subject' => $subject
);

$mime = new Mail_mime("
");
$mime->setTXTBody($message);

$file = "/path/to/attachment.pdf";
$mime->addAttachment($file, 'application/pdf');

$body = $mime->get();
$headers = $mime->headers($headers);

$mail = Mail::factory('smtp', array(
    'host' => $host,
    'auth' => true,
    'username' => $username,
    'password' => $password
));

$mail->send($to, $headers, $body);

if(mail($to, $subject, $message, $headers)) {
    echo "邮件发送成功！";
} else {
    echo "邮件发送失败，请检查配置信息！";
}