A catch-all functionality that is activated for a given mailbox will allow you to receive email messages that are sent to addresses that do not actually exist. To state it differently, if you deactivate an email address and somebody still sends an email message to it, or to any misspelled address under the very same domain, you’ll receive the email in the catch-all mailbox. Using this functionality means that you won’t miss an email for any reason, which could be vital in case you are running a company, for instance. Since you may start receiving junk messages, you can use the catch-all option with anti-spam filtering software so as to receive only authentic messages in your inbox. Only one single mailbox per domain name can be a catch-all one and email forwarding cannot be activated for a catch-all mailbox.