Api Path

If you use an older 2sxc Version than 9.35 you have to move the api folder one level up and edit the path in api/FormController.cs

var path = System.IO.Path.Combine("~", App.Path, getEdition() , "api/Parts", fileName);

to

var path = System.IO.Path.Combine("~", App.Path, "api/Parts", fileName);

Mail Labels

At the SubmitType you can add nicer naming for your email templates. 

Its a Key=String combination. The key is your ContentType Fieldname and the String is the nicer naming in your email template. If you don't put anything in it you will see the Fieldname.

Cache

While developing I had problems with the DNN cache. Be sure the cache is disabled or that you empty it after making changes.

File Upload

If you want to use a file upload you have to set some permissions on your field.