1. Go to this page and download the library: Download atelierspierrot/mime-mailer library. Choose the download type require.
2. Extract the ZIP file and open the index.php.
3. Add this code to the index.php.
<?php
require_once('vendor/autoload.php');
/* Start to develop here. Best regards https://php-download.com/ */
$mailer->getMessage() // the current message object
$mailer->getTransporter() // the current transporter object
$mailer->getSpooler() // the current spooler object
$mailer->getMessage() // the message will be created if none was defined
->setTo(...)
->setSubject(...)
->setText(...)
//...
;