I tried your amended code but it's still not working. If the checkbox is left un-ticked nothing shows up in the email??
I'm working directly in code view in the waue_freelancer-registration_1.php file. I made the changes then selected the main page file to upload via ftp (freelancer-registration.php) with related files set to upload automatically. I noticed in the FTP log that it didn't transfer the waue_freelancer-registration_1.php file even though I'd just made changes, it said 'same, not transferred' in the status report, so I manually uploaded the file.
One other thing I've noticed is that if I try to edit the contents of the email through the Universal Email interface there is no 'if..then..else' code in the email page. I think it's using this code rather than the code I'm manually typing in without using UE as this code simply says write the value of the form field in the email, which if not checked is blank. Would you agree?