If your email that you setup still exists (you have not cancelled or deleted it) and it is working, then the email will just get delivered, even if you have no computer or smartphone to view it on.
If the email that you setup has been deleted or you cancelled your broadband supplier and they then deleted your email address then the person who sends an email will get some sort of "undeliverable" message.
It will only be delivered to your account if you still have an account. If you do, they won't know either way, but if you don't, it will be bounced back as undeliverable.
Unfortunately, some e-mail service providers do not instigate a "bounce" protocol when an address is no longer in use. I had addresses with BT over a decade ago which I then asked to be cancelled and even now any message sent there simply disappears into the ether - no indication that any of them is no longer in use comes back.