使用SMTP客户端发送电子邮件

// Create an Email Object. The Email Object can also
// be created without specifying any parameters.
$email = new \FastSitePHP\Net\Email($from, $to, $subject, $body);

// All properties can be read and set through getter/setter functions.
$email
    ->allowUnicodeEmails(true) // For support with Unicode Email Addresses
    ->from(['无回复@example.com', 'No Reply'])
    ->replyTo('test@example.com')
    ->to(['email1@example.com', 'email2@example.com'])
    ->cc('email3@example.com')
    ->bcc('email4@example.com')
    ->priority('High') // ['High', 'Normal', or 'Low']
    ->safeHeaderNames(true) // Defaults to [true] for custom fields
    ->header('X-Transaction-ID', '123abc')
    ->encodeFileNames(true)
    ->attachFile($file_path)
    ->isHtml(true) // Defaults to [true]
    ->subject($subject)
    ->body($body);

// Send email using Simple Mail Transfer Protocol (SMTP).
// Setting [$smtp = null] after use, automatically calls [$smtp->quit()]
// and [$smtp->close()], however it also happens automatically after the
// object is no longer used.
$smtp = new \FastSitePHP\Net\SmtpClient($host, $port);
if ($user) {
    $smtp->auth($user, $password);
}
$smtp->send($email);
$smtp = null;

// Create a Client with a 2 second timeout and with debugging
// to show all data sent to the SMTP Server and all reply lines
$timeout = 2;
$callback = function($message) {
    echo '[' . date('H:i:s') . '] ' . trim($message) . "\n";
};
$smtp = new \FastSitePHP\Net\SmtpClient($host, $port, $timeout, $callback);