To include custom field data in the notification email, here's the format:
First name: [[first_name]]
Last name: [[last_name]]
Full name: [[full_name]]
Message: [[custom_1]]
Reason: [[custom_2]]
[[custom_x]] where x is the number of the custom field.
You will find the number when you edit the custom field and URL will show the number:
http://yourdomain.com/a.php/custom_fields/edit/x
Where x is the number in [[custom_x]]