UserForms saves the 'referrer' as a hidden text field. Is it possible to get this into the mail?
Not easily in the module. You would have to edit the core UserDefinedForm.php file and add a line around 569 to add the referrer to the list
// new code $referrer = new SubmittedFormField(); $referrer->Name = "Referrer"; $referrer->Title = "Referrer"; $referrer->Value = urlencode($data['Referrer']); $referrer->write(); $submittedFields->push($referrer); // existing code $emailData = array( "Sender" => Member::currentUser(), "Fields" => $submittedFields );