lightning address has affordance as an email. will not be able to receive money if your inbox is full, like mail.

This is good affordance! Even if liquidity isn't enough and you can't receive money, don't upset, because mail is as that is. It's time for you to look for or develop a provider that offers large inbox.

In the old days, free mail had small inbox, but then gmail came along with its huge inbox and took over the world.