I think you are allowed to have 5 email addresses tied to your business PayPal account that people can send money to. What happens when you need more than that? I know you can't have more than one PayPal business account so what do you do?
From my knowledge, there's nothing else you could do except for removing one to add another. Hence, the ability to add only a certain amount of email addresses.
As far as i know you are allowed to have up to EIGHT email addresses there in your paypal account not FIVE. DON.
Since the question was what happens when you've exceeded the limit, you can't add any more beyond that. You can either delete one and add another, or you could use one to receive payments from multiple 'sources'.
I think it's 8 as well. Paypal in my experience has said this is sufficient and is the right amount for legitimate paypal use, short of fraud. I wish you could add more addresses as well!