After an invoice is sent, it shows 4 options above the invoice, sent, viewed, paid and deposited, I have never had a tick in the viewed box, can you tell me why please

Hi Woodfordjoinery, Welcome to the Community! In order for viewed to be ticked the person who receives the invoice has to click on view invoice, which then forwards to a link and brings up a pop-up of the invoice. If the person just looks at the email and the cost on the front it will not pick up as viewed. I hope this makes sense. Any Q's just reply back on this thread😊