A catch-all functionality that is enabled for a specific email mailbox will allow you to receive emails that are sent to email addresses that do not actually exist. Otherwise stated, if you deactivate an email address and someone still sends an email message to it, or to any miswritten email address under the very same domain name, you will get the message in the catch-all mailbox. Using this functionality means that you won’t miss an email for any reason whatsoever, which could be essential in case you are running a business, for example. Since you may start receiving spam emails, you can combine the catch-all feature with anti-spam filters in order to get only real emails in your inbox. Only one single mailbox per domain can be a catch-all one and email forwarding cannot be set up for a catch-all mailbox.