It almost works!!
I have approved and completed as check boxes with different emails to be sent.
The approved (only) one works great!
The approved and completed (both boxes ticked) email, however I get an approved email as well presumably because the approved and completed boxes are (and need) to be ticked.
Is there a way to say send email a if box 1 is ticked, but do not send if box 2 is ticked.
Then leave the second email to send if both boxes are ticked as it does now?