Just checking through your code and it would seem you are not using PHPMailer but X-Mailer instead. From my point of view the PHPMailer is a better way to go and my code is based on that. All the differences are based on that selection you have made. Only other difference I found was that your form is in a layout grid, but I can't imagine that makes a difference.
AlsoHave you selected - Advanced, Mail engine, Use PHPMailer instead of standard PHP mail, also Mail Engine, mail. This is found by right clicking on a blank part of the form and selecting object properties then clicking on the Advanced button
Don't forget to change 'my email name' in the custom code to something more meaningful to you i.e. 'Mike's Site"$mail->FromName = 'my email name';
Other than that, have nothing further to offer.
Regards
Roger