With Mime Mail to send HTML mail

I have been using PHPMailer for transporting email for a long time.
It works perfectly in sending plain text but recently I found a need to send html email.

So I start to try working it with Mime email module. Following the instructions in README.txt, I first uncheck "Use PHPMailer to send e-mails" on PHPMailer settings page.
But on mime email settings page, there is no PHPMailer email engine option to choose from.

Do I miss something?

Thousand thanks,