A catch-all functionality that is activated for a particular mailbox will permit you to receive email messages that are sent to email addresses that do not really exist. To state it differently, if you deactivate an email address and somebody still sends an email to it, or to any misspelled email address under the exact same domain, you’ll receive the email in the catch-all mailbox. Using this feature means that you won’t miss an email for any reason, which could be crucial in case you run a business, for example. Since you may begin receiving spam messages, you can use the catch-all option with anti-spam filters so as to receive only legitimate messages in your inbox. Just one single mailbox per domain name can be a catch-all one and email forwarding cannot be activated for a catch-all mailbox.