I'm not able to test out your form, I cannot get past the phone validation. I'm including a screen shot of what the form looks like when I try to enter the number that you have entered into the form.
If I could get past this part I would be able to check my inbox for an email, but I have not been able to do so yet. In all of my testing of the URSP and UE4 by itself I'm able to receive the .co.uk emails without issue. If you are able to get mail sent to other email addresses then it would seem that the script is executing as it should. There is nothing present in the URSP or UE4 that would prevent emails from going to .co.uk addresses.
If you can please remove the validations from this field temporarily so that I can test the form out with multiple addresses to see what the result is.