I suppose it can, it just feels to me somewhat deceptive declaring 'this recipient doesn't exist' when the email address is correct and valid for me, it's just

I suppose it can, it just feels to me somewhat deceptive declaring 'this recipient doesn't exist' when the email address is correct and valid for me, it's just that the other user who filled out the form on their site is a moron. Also I'd be worried about ramifications if I sometime later did want to fill out their form for whatever they're offering, would it still accept it, or would it go 'nope, you don't exist, walk on'