It should only take a few minutes. Some email servers automatically reject emails the first time it gets them, hoping that legitimate emails will be retried but spam will not be. My mail server retries after something like 3 hours.
Often the problem is that you've typed your email in wrong or an old email address that you no longer use was attached to your paypal account.
If you don't get it within a few hours, email support at blockland dot us.