A catch-all functionality that is activated for a particular email mailbox will permit you to receive emails that are sent to email addresses that do not actually exist. Otherwise put, if you disable an email address and someone still sends a message to it, or to any mistyped address under the exact same domain name, you will get the message in the catch-all mailbox. Using this functionality implies that you won’t miss an email for any reason whatsoever, which could be essential in case you are running a business, for instance. Since you may begin receiving unsolicited email messages, you can use the catch-all option with anti-spam filters in order to receive only real emails in your inbox. Only one mailbox per domain can be a catch-all one and email forwarding cannot be enabled for a catch-all mailbox.