A catch-all functionality that is activated for a specific mailbox will allow you to receive email messages that are sent to email addresses that do not actually exist. To state it differently, if you delete an email address and someone still sends an email to it, or to any mistyped address under the very 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, which could be crucial in case you are running a business, for instance. Since you may begin receiving junk email messages, you can use the catch-all functionality with anti-spam filters so as to receive only real email messages in your inbox. Only one single mailbox per domain can be a catch-all one and email forwarding cannot be enabled for a catch-all mailbox.