Sending HTML Elements trough SMTP

Hello Again,
I get a problem…
How can I send HTML Elements by email?
I actually downloaded the phpmailer and SMTP on GitHub… (GitHub - InfinityFreeHosting/contactform: Simple contact form with PHPMailer)
there are so many codes and I don’t know where I must change things.
currently, HTML codes on emails are just texts, so I want to make them like Real Elements.
I changed the Message here:

You can use $mail->IsHTML(true); after the body has been created. So in your case, it would be:

$mail->Subject = $_POST["subject"];
$mail->Body = '<html lang="en"><p style="color: lime">Here is the message!</p><be></html>';

tysm <3