What I did is I placed a new form and entered the data needed. This works.
I think the old form is somehow damaged because nothing worked. I hid the old form, so if you want you can compare them.
The {{email}} is the senders adress and is used as a CC when sending the mail, so he gets a copy too when sending his mail with the webform.
Uppercase mailadresses are no problem.
I did notice however that when you fill in the form online, and if you enter the recipient mail adress for the email, it gives an error. This is something for Joomshaper to keep in mind. It shouldn't give any problems however, because this can only hapen with the tester of the site. Using the global config adres in this mail adres line does not give any problems.
So I advise placing a new form and re-entering the data.